Marco Zennaro

An overview of emerging results in cooperative UAV control

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.

The software architecture of the Berkeley UAV Platform

This paper details the software architecture of the Berkeley unmanned aerial vehicle (UAV) platform. Developed over the course of three years, this platform has successfully demonstrated autonomous vision-based navigation and obstacle avoidance. A software architecture has been developed to allow for collaborative control concepts to be examined. This modular architecture has been shown to be effective for use in allowing a team of UAVs to collaboratively perform a set of missions. The performance of the architecture was demonstrated using 3 UAVs to perform autonomous collaborative patrolling and vision-based navigation

CSL: A Language to Specify and Re-specify Mobile Sensor Network Behaviors

The Collaborative Sensing Language (CSL) is a high-level feedback control language for mobile sensor networks (MSN). It specifies MSN controllers to accomplish network objectives with a dynamically changing ad-hoc resource pool. Furthermore, CSL is designed to allow the updating of controllers during execution (patching). This enables hierarchical control with simpler controllers at lower levels. The CSL Execution Engine contains the intelligence to allocate resources to tasks dynamically and adjust in real time to resource motion, this enables CSL controllers to be simple, intuitive and scalable. Experimental results show that the CSL Execution Engine performs these services with the addition of very little overhead.

A Modular Software Infrastructure for Distributed Control of Collaborating UAVs

Collaborating unmanned aerial vehicles can e‐ciently perform surveillance, mapping, and other tasks without human risk. Currently deployed unmanned aerial vehicles demonstrate a need for increased autonomy and cooperation. We present a UAV software architecture and hardware platform that have demonstrated single-user control of a ∞eet of aircraft, distributed task assignment, and vision-based navigation. A modular software infrastructure has been developed to coordinate distributed control, communications, and vision-based control. Along with the onboard control architecture, a set of user interfaces has been developed to allow a single user to e‐ciently control the ∞eet of aircraft. Distributed and vision-based control are enabled by powerful onboard computing capability and an aircraft-to-aircraft ad-hoc wireless network. Custom modiflcations to the Sig Rascal airframe are required to support this capability, including reinforcement and vibration isolation. We describe original elements of the system that provide unique capabilities for collaboration, followed by results of a ∞ight demonstration.

An architecture for UAV team control

Abstract Recent years has seen a widespread interest in the use of Unmanned aircraft vehicles for military applications. These UAVs can be used in many applications such as surveillance, information gathering, suppression of enemy defenses, air to air combat, mapping buildings and facilities etc. In this paper, we present an architecture with the necessary algorithms that we have implemented to control a team of UAVs to search for targets such as SAMs, ground troops, artillery, tanks etc in a given region.

Distributing synchronous programs using bounded queues

This paper is about the modular compilation and distribution of a sub-class of Simulink programs [9] across networks using bounded FIFO queues. The problem is first addressed mathematically. Then, based on these formal results, a software library for the modular compilation and distribution of Simulink programs is given. The performance of the library is given. The value of synchronous programming for the next generation of traffic control is discussed. The adoption of these tools seems to be the natural candidate to address the needs of traffic engineers. As a case study we present an implementation in Simulink of a controller for coordinated traffic signals in an asymmetric peak hour traffic scenario and we evaluate its computational performance in a distributed environment.

A service network architecture for a multi-vehicle search mission

Multi-vehicle applications rely on the dynamic allocation of resources, and must exhibit robustness to failures or to service degradation in general. We present a model for such applications, called the service network model. The entities of this model are services and service providers. Services are defined by standard names and interfaces, and are described by attributes. Service providers export services with certain quality of service guarantees. They may also need to import services from other providers. An application is modeled as a directed graph, where nodes represent service providers and edges represent services imported by the source node and exported by the destination node. The problem is then to build such application graphs dynamically. We provide a middleware and an algorithm that solves the above problem. Functions of the middleware include publishing, finding and using service providers, as well as completing an incomplete application graph with the missing services. We illustrate our approach with a case study involving a multi-vehicle search mission.

Distributing synchronous systems with modular structure

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.