Person:

Egerstedt, Magnus B.

Permanent Link

https://hdl.handle.net/1853/72204

Associated Organization(s)

Organizational Unit

School of Electrical and Computer Engineering

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Now showing 1 - 8 of 8

Probabilistic Life Time Maximization of Sensor Networks

(Georgia Institute of Technology, 2013-02) Jaleel, Hassan ; Rahmani, Amir R. ; Egerstedt, Magnus B.

The design of power-aware lifetime maximization algorithms for sensor networks is an active area of research. However, the standard assumption is that the performance of the sensors remains the same throughout the network’s lifetime, which is not alwaystrue. In this paper, we study the effects of power decay on the performance of individual sensors as well as of the entire network. In particular, we examine networks with decaying footprints, akin to those of RF or radar-based sensors and relate the performance of a sensor to its available power. Moreover, we propose probabilistic scheduling controllers that compensate for the effects of the decrease in power while maintaining an adequate probability of event detection under two sensing models; Boolean and non-Boolean. We simulate the performance of the proposed controllers to establish that the desired performance levels are indeed maintained throughout the lifetime of the network.
Merging and Spacing of Heterogeneous Aircraft in Support of NextGen

(Georgia Institute of Technology, 2012-09) Chipalkatty, Rahul ; Twu, Philip Y. ; Rahmani, Amir R. ; Egerstedt, Magnus B.

FAA’s NextGen program aims to increase the capacity of the national airspace, while ensuring the safety of aircraft. This paper provides a distributed merging and spacing algorithm that maximizes the throughput at the terminal phase of flight, using infor- mation communicated between neighboring aircraft through the ADS-B framework. Aircraft belonging to a mixed fleet negotiate with each other and use dual decomposi- tion to reach an agreement on optimal merging times, with respect to a pairwise cost, while ensuring proper inter-aircraft spacing for the respective aircraft types. A set of sufficient conditions on the geometry and operating conditions of merging forks are provided to identify when proper inter-aircraft spacing can always be achieved using the proposed algorithm for any combination of merging aircraft. Also, optimal de- centralized controllers are derived for merging air traffic when operating under such conditions. The performance of the presented algorithm is verified through computer simulations.
Geometric Foraging Strategies in Multi-Agent Systems Based on Biological Models

(Georgia Institute of Technology, 2010-12) Haque, Musad A. ; Rahmani, Amir R. ; Egerstedt, Magnus B.

In nature, communal hunting is often performed by predators by charging through an aggregation of prey. However, it has been noticed that variations exist in the geometric shape of the charging front; in addition, distinct differences arise between the shapes depending on the particulars of the feeding strategy. For example, each member of a dolphin foraging group must contribute to the hunt and will only be able to eat what it catches. On the other hand, some lions earn a "free lunch" by feigning help and later feasting on the prey caught by the more skilled hunters in the foraging group. We model the charging front of the predators as a curve moving through a prey density modeled as a reaction-diffusion process and we optimize the shape of the charging front in both the free lunch and no-free-lunch cases. These different situations are simulated under a number of varied types of predator-prey interaction models, and connections are made to multi-agent robot systems.
Optimal Motion Primitives for Multi-UAV Convoy Protection

(Georgia Institute of Technology, 2010-05) Rahmani, Amir R. ; Ding, Xu Chu ; Egerstedt, Magnus B.

In this paper we study the problem of controlling a number of Unmanned Aerial Vehicles (UAVs) to provide convoy protection to a group of ground vehicles. The UAVs are modeled as Dubins vehicles flying at a constant altitude with bounded turning radius. This paper first presents time-optimal paths for providing convoy protection to static ground vehicles. Then this paper addresses paths and control strategies to provide convoy protection to ground vehicles moving on a straight line. Minimum numbers of UAVs required to provide perpetual convoy protection for both cases are derived.
Multi-UAV Convoy Protection: An Optimal Approach to Path Planning and Coordination

(Georgia Institute of Technology, 2010) Ding, Xu Chu ; Rahmani, Amir R. ; Egerstedt, Magnus B.

In this paper we study the problem of controlling a group of Unmanned Aerial Vehicles (UAVs) to provide convoy protection to a group of ground vehicles. The UAVs are modeled as Dubins vehicles flying at a constant altitude with bounded turning radius. We first present time-optimal paths for providing convoy protection to stationary ground vehicles. Then we propose a control strategy to provide convoy protection to ground vehicles moving on straight lines. The minimum number of UAVs required to provide perpetual convoy protection in both cases are derived.
A Hybrid, Multi-Agent Model of Foraging Bottlenose Dolphins

(Georgia Institute of Technology, 2009-09) Haque, Musad A. ; Rahmani, Amir R. ; Egerstedt, Magnus B.

Social behavior of animals can offer solution models for missions involving a large number of heterogeneous vehicles, such as light combat ships, unmanned aerial vehicles, and unmanned underwater vehicles. We draw inspiration from the foraging techniques of bottlenose dolphins to address the problem of heterogeneous multi-agent herding. We produce a hybrid automaton model of the entire foraging method - search, detect, and capture - where agents are modeled as first-order systems in which interactions are defined through spatial proximity. Finally, simulations are provided to illustrate that our model is expressive enough to capture this complex biological phenomenon.
Optimal Multi-UAV Convoy Protection

(Georgia Institute of Technology, 2009-04) Ding, Xu Chu ; Rahmani, Amir R. ; Egerstedt, Magnus B.

In this paper, we study time-optimal trajectories for Unmanned Aerial Vehicles (UAVs) to provide convoy protection to a group of stationary ground vehicles. The UAVs are modelled as Dubins vehicles flying at a constant altitude. Due to kinematic constraints of the UAVs, it is not possible for a single UAV to provide convoy protection indefinitely. In this paper, we derive time-optimal paths for a single UAV to provide continuous ground convoy protection for the longest possible time. Furthermore, this paper provides optimal trajectories for multiple UAVs to achieve uninterrupted convoy protection. The minimum number of UAVs required to achieve this task is determined.
Controllability of Multi-Agent Systems from a Graph-Theoretic Perspective

(Georgia Institute of Technology, 2009-02) Rahmani, Amir R. ; Ji, Meng ; Mesbahi, Mehran ; Egerstedt, Magnus B.

In this work, we consider the controlled agreement problem for multi-agent networks, where a collection of agents take on leader roles while the remaining agents execute local, consensus-like protocols. Our aim is to identify reflections of graph-theoretic notions on system-theoretic properties of such systems. In particular, we show how the symmetry structure of the network, characterized in terms of its automorphism group, directly relates to the controllability of the corresponding multi-agent system. Moreover, we introduce network equitable partitions as a means by which such controllability characterizations can be extended to the multileader setting.