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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Publication Search Results

Now showing 1 - 10 of 13

Pancakes: A Software Framework for Distributed Robot and Sensor Network Applications

(Georgia Institute of Technology, 2013) Martin, Patrick ; de la Croix, Jean-Pierre ; Egerstedt, Magnus B.

The development of control applications for multi-agent robot and sensor networks is complicated by the heterogeneous nature of the systems involved, as well as their physical capabilities (or limitations).We propose a software framework that unifies these networked systems, thus facilitating the development of multiagent control across multiple platforms and application domains. This framework addresses the need for these systems to dynamically adjust their actuating, sensing, and networking capabilities based on physical constraints, such as power levels.Furthermore, it allows for sensing and control algorithms to migrate to different platforms, which gives multi-agent control application designers the ability to adjust sensing and control as the network evolves. This paper describes the design and implementation of our software system and demonstrates its successful application on robots and sensor nodes, which dynamically modify their operational components.
Graph Process Specifications for Hybrid Networked Systems

(Georgia Institute of Technology, 2012-12) Twu, Philip Y. ; Martin, Patrick ; Egerstedt, Magnus B.

Many large-scale multi-agent missions consist of a sequence of subtasks, each of which can be accomplished separately by having agents execute appropriate decentralized controllers. However, many decentralized controllers have network topological prerequisites that must be satisfied in order to achieve the desired effect on a system. Therefore, one cannot always hope to accomplish the original mission by having agents naively switch through executing the controllers for each subtask. This paper extends the Graph Process Specification (GPS) framework, which was presented in previous work as a way to script decentralized control sequences for agents, while ensuring that network topological requirements are satisfied when each controller in the sequence is executed. Atoms, the fundamental building blocks in GPS, each explicitly state a network topological transition. Moreover, they specify the means to make that transition occur by providing a multi-agent controller, as well as a way to locally detect the transition. Scripting a control sequence in GPS therefore reduces to selecting a sequence of atoms from a library to satisfy network topological requirements, and specifying interrupt conditions for switching. As an example of how to construct an atom library, the optimal decentralization algorithm is used to generate atoms for agents to track desired multi-agent motions with when the network topology is static. The paper concludes with a simulation of agents performing a drumline-inspired dance using decentralized controllers generated by optimal decentralization and scripted using GPS.
Hybrid Systems Tools for Compiling Controllers for Cyber-Physical Systems

(Georgia Institute of Technology, 2011-09-15) Martin, Patrick ; Egerstedt, Magnus B.

In this paper, we consider the problem of going from high-level specifications of complex control tasks for cyber-physical systems to their actual implementation and execution on physical devices. This transition between abstraction levels inevitably results in a specification-to-execution gap, and we discuss two sources for this gap; namely model based and constraint based. For both of these two types of sources, we show how hybrid control techniques provide the tools needed to compile high-level control programs in such a way that the specification-to-execution gap is removed. The solutions involve introducing new control modes into nominal strings of control modes as well as adjusting the control modes themselves.
Constructing and Implementing Motion Programs for Robotic Marionettes

(Georgia Institute of Technology, 2011-04) Martin, Patrick ; Johnson, Elliot ; Murphey, Todd D. ; Egerstedt, Magnus B.

This technical note investigates how to produce control programs for complex systems in a systematic manner. In particular, we present an abstraction-based approach to the specification and optimization of motion programs for controlling robot marionettes. The resulting programs are based on the concatenation of motion primitives and are further improved upon using recent results in optimal switch-time control. Simulations as well as experimental results illustrate the operation of the proposed method.
Pancakes: A Software Framework for Distributed Robot and Sensor Network Applications

(Georgia Institute of Technology, 2010-11) Martin, Patrick ; de la Croix, Jean-Pierre ; Egerstedt, Magnus B.

The development of control applications for multi-agent robot and sensor networks is complicated by the heterogeneous nature of the systems involved, as well as their physical capabilities (or limitations). We propose a software framework that unifies these networked systems, thus facilitating the development of multi-agent control across multiple platforms and application domains. This framework addresses the need for these systems to dynamically adjust their actuating, sensing, and networking capabilities based on physical constraints, such as power levels. Furthermore, it allows for sensing and control algorithms to migrate to different platforms, which gives multi-agent control application designers the ability to adjust sensing and control as the network evolves. This paper describes the design and implementation of our software system and demonstrates its successful application on robots and sensor nodes, which dynamically modify their operational components.
Graph Process Specifications for Hybrid Networked Systems

(Georgia Institute of Technology, 2010-08) Martin, Patrick ; Egerstedt, Magnus B. ; Twu, Philip Y.

Research in multi-agent systems has supplied a diverse collection of decentralized controllers to accomplish specific tasks. When agents execute a sequence of these controllers, the network behaves as a hybrid system, where the dynamics in each mode evolve according to a single controller in the sequence. This paper presents a formal specification for such a system that describes the underlying graph process associated with the information flow amongst agents in each mode. Since many decentralized controllers require specific information graph topologies in order to function properly, a problem that arises is that the information graph at the termination of one mode may not be sufficient to initiate the next mode in the sequence.We propose a Graph Process Specification (GPS) framework that describes the graph process. Furthermore, if two modes cannot be executed consecutively, a GPS provides a way to determine which modes can be inserted in between them to make the resulting sequence executable. We formally define a GPS, describe its execution, and provide examples that showcase its usage in composing together multiple decentralized controllers within a multi-agent system.
Power-Aware Sensor Coverage: An Optimal Control Approach

(Georgia Institute of Technology, 2010-07) Martin, Patrick ; Galvan-Guerra, Rosalba ; Egerstedt, Magnus B. ; Azhmyakov, Vadim

Sensor networks primarily have two competing objectives: they must sense as much as possible, yet last as long as possible when deployed. In this paper, we approach this problem using optimal control. We describe a model that relates each sensor’s “footprint” to their power consumption and use this model to derive optimal control laws that maintain the area coverage for a specified operational lifetime. This optimal control approach is then deployed onto different sensor networks and evaluated for its ability to maintain coverage during their desired lifetime.
Motion Programs for Multi-Agent Control: From Specification to Execution

(Georgia Institute of Technology, 2010-07) Martin, Patrick ; Egerstedt, Magnus B.

This paper explores the process of turning high-level motion programs into executable control code for multi-agent systems. Specifically, we use a modified Motion Description Language (MDL) for networked systems that can specify motion programs for a collection of autonomous agents. This MDL includes the network information dependencies required for each agent to perform coordinated behaviors. We discuss the design of this framework and the language theoretic tools used to analyze the information dependencies specified by these multi-agent motion programs. Additionally, we develop a supervisor system that monitors the behavior of the agents on the network, and prevents the agents from entering into states where information dependencies are violated. We demonstrate our framework using a simulated multi-robot system.
Timing Control of Switched Systems with Applications to Robotic Marionettes

(Georgia Institute of Technology, 2010-05) Martin, Patrick ; Egerstedt, Magnus B.

We present an optimal timing control formulation for the problem of controlling autonomous puppets. In particular, by appropriately timing the different movements, entire plays can be performed. Such plays are produced by concatenating sequences of motion primitives and a compiler optimizes these sequences, using recent results in optimal switch-time control. Additionally, we apply saddle-point techniques to approach the problem of timing constraints among interconnected puppets. Experimental results illustrate the operation of the proposed methods.
Optimization of Multi-Agent Motion Programs with Applications to Robotic Marionettes

(Georgia Institute of Technology, 2009-04) Martin, Patrick ; Egerstedt, Magnus B.

In this paper, we consider the problem of generating optimized, executable control code from high-level, symbolic specifications. In particular, we construct symbolic control programs using strings from a motion description language with a nominal set of motion parameters, such as temporal duration and energy, embedded within each mode. These parameters are then optimized over, using tools from optimal switch-time control and decentralized optimization of separable network problems. The resulting methodology is applied to the problem of controlling robotic marionettes, and we demonstrate its operation on an example scenario involving symbolic puppet plays defined for multiple puppets.