Christopher Rouff | Johns Hopkins University Applied Physics Lab (original) (raw)

Papers by Christopher Rouff

NASA monographs in systems and software engineering, 2009

Having focused on automation and autonomy in space-based systems in the previous chapter, attenti... more Having focused on automation and autonomy in space-based systems in the previous chapter, attention is now directed toward ground-based systems, particularly the automation of spacecraft control centers. We describe a strategy for automating NASA ground-based systems by using a multiagent system to support ground-based autonomous satellite-subsystem monitoring and report generation supporting mission operations. Over the last several years, work has

NASA is studying advanced technologies for a future robotic exploration mission to the asteroid b... more NASA is studying advanced technologies for a future robotic exploration mission to the asteroid belt. This mission, the prospective ANTS (Autonomous Nano Technology Swarm) mission, will comprise of 1,000 autonomous robotic agents designed to cooperate in asteroid exploration. The emergent properties of swarm type missions make them powerful, but at the same time are more dflcult to design and assure that the proper behaviors will emerge. We are currently investigating formal methods and techniques for verification and validation of future swarm-based missions. The advantage of using formal methods is their ability to mathematically assure the behavior of a swarm, emergent or otherwise. The ANT mission is being used as an example and case study for swarm-based missions for which to experiment and test current formal methods with intelligent swam. Using the ANTS mission, we have evaluated multiple formal methods to determine their effectiveness in modeling and assuring swarm behavior.

NASA monographs in systems and software engineering, 2009

In this chapter, we discuss the application of the autonomy technologies considered in previous c... more In this chapter, we discuss the application of the autonomy technologies considered in previous chapters to spacecraft constellations. The needs of constellations that can be supported by onboard autonomy are described along with the enhancements attainable by constellation missions through the application of onboard autonomy. A list of hypothetical constellation mission types is also posed and a list of governance concepts is then presented in relation to the degree of central control being exercised on the constellation. Finally, the chapter discusses mobile agent concepts to support autonomic constellations.

Springer eBooks, 2009

In this chapter, we examine how agent technology might be utilized in flight software (FSW) to en... more In this chapter, we examine how agent technology might be utilized in flight software (FSW) to enable increased levels of autonomy in spacecraft missions. Again, as stated in the Preface, our discussion relates exclusively to uncrewed assets (robotic spacecraft, instrument platforms on planetary bodies, robotic rovers, etc.) or assets that must be capable of untended operations (e.g., ground stations during

Springer eBooks, Oct 10, 2009

Having focused on automation and autonomy in space-based systems in the previous chapter, attenti... more Having focused on automation and autonomy in space-based systems in the previous chapter, attention is now directed toward ground-based systems, particularly the automation of spacecraft control centers. We describe a strategy for automating NASA ground-based systems by using a multiagent system to support ground-based autonomous satellite-subsystem monitoring and report generation supporting mission operations. Over the last several years, work has progressed on developing prototypes of agent-based control centers [2, 36, 86, 134]. With the prototypes has come an improved understanding of the potentials for autonomous ground-based command and control activities that could be realized from the innovative use of agent technologies. Three of the prototypes will be described: Agent-based Flight Operations Associate (AFLOAT), Lights Out Ground Operations System (LOGOS), and Agent Concept Testbed (ACT).

NASA is investigating new paradigms for future space exploration, heavily focused on the (still) ... more NASA is investigating new paradigms for future space exploration, heavily focused on the (still) emerging technologies of autonomous and autonomic systems [47, 48, 49]. Missions that rely on multiple, smaller, collaborating spacecraft, analogous to swarms in nature, are being investigated to supplement and complement traditional missions that rely on one large spacecraft [16]. The small spacecraft in such missions would each be able to operate on their own to accomplish a part of a mission, but would need to interact and exchange information with the other spacecraft to successfully execute the mission. This new systems paradigm offers several advantages: • the ability to explore environments and regions in space where traditional craft would be impractical,

The problem of maintaining a desired number of mobile agents on a network is not trivial, especia... more The problem of maintaining a desired number of mobile agents on a network is not trivial, especially if we want a completely decentralized solution. Decentralized control makes a system more r e bust and less susceptible to partial failures. The problem is exacerbated on wireless ad hoc networks where host mobility can result in significant changes in the network size and topology. In this paper we propose an ecology-inspired approach to the management of the number of agents. The approach associates agents with living organisms and tasks with food. Agents procreate or die based on the abundance of uncompleted tasks (food). We performed a series of experiments investigating p r o p erties of such systems and analyzed their stability under various conditions. We concluded that the ecology based metaphor can be successfully applied to the management of agent populations on wireless ad hoc networks. 3 Problem Formulation 3.1 Motivation In a typical dynamic ad hoc network there is limited, variable bandwidth between hosts, and the memory and CPU on each host is constrained. Given this dynamic and resource constrained environment, it is impractical to prescribe any precomputed solution. The solution we propose for such networks is to create a system that can control the number of agents dynamically, adapting to the ever-changing environment. In order to work in the context of an agent based system, a control system should be distributed and decentralized. By distributed, we mean that the system should be able to use the underlying network to parallelize problem solving on multiple hosts. By decentralized, we mean that the system should avoid reliance on a single node, and should allow each agent to act independently. The emergent behavior resulting from the individual localized control decisions ideally will yield an optimal, or near-optimal, solution at the global level. 3.2 Approach Large ecosystems usually have several attractive qualities (such as dynamic decentralized control, self regulation, no single point of failure, robustness, and stability) that we require for our system. We propose a solution to the problem of determining the number of agents appropriate for a task at hand that is inspired by large ecosystems: 1. Each task in our system is associated with food. 2. Agents which successfully complete a task collect the associated food points. 3. Agents consume food points over time to sustain their existence. 4. Agents that exhaust their supply of food die. 5. An abundance of food can cause a new agent to spawn. I " All of these techniques promise to improve on the current research and provide a more stable decentralized ways to control the number of agents on a wireless ad hoc network. 5.2 Conclusions This paper developed an ecology-based model for managing the number of agents on ad hoc wireless networks. We have discovered that an ecosystem based model can provide decentralized distributed robust control of agents in dynamic and uncertain network environments. Our approach involves a novel exploitation of properties of ad hoc networks, enabling mobile agents to automatically adapt to changes that affect their communication and migration. The capability to dynamically adjust to the state of their network provides new possibilities for stable MAS.

NASA monographs in systems and software engineering, 2017

Casimir interactions play an important role in the dynamics of nanoscale objects. Here, we invest... more Casimir interactions play an important role in the dynamics of nanoscale objects. Here, we investigate the noncontact transfer of angular momentum at the nanoscale through the analysis of the Casimir torque acting on a chain of rotating nanoparticles. We show that this interaction, which arises from the vacuum and thermal fluctuations of the electromagnetic field, enables an efficient transfer of angular momentum between the elements of the chain. Working within the framework of fluctuational electrodynamics, we derive analytical expressions for the Casimir torque acting on each nanoparticle in the chain, which we use to study the synchronization of chains with different geometries and to predict unexpected dynamics, including a "rattleback"-like behavior. Our results provide insights into the Casimir torque and how it can be exploited to achieve efficient noncontact transfer of angular momentum at the nanoscale, and therefore have important implications for the control and manipulation of nanomechanical devices.

NASA monographs in systems and software engineering, 2017

Unlike our first topic, attitude, orbit is a word for which most people probably could conjure up... more Unlike our first topic, attitude, orbit is a word for which most people probably could conjure up a reasonable visual image. They might envision the Earth and the other planets circling the Sun, or the Moon or a spacecraft circling the Earth.

NASA monographs in systems and software engineering, 2017

In addition to reviving the classic “buddy picture” genre, as well as making Paul Newman and Robe... more In addition to reviving the classic “buddy picture” genre, as well as making Paul Newman and Robert Redford two of the top box office draws in Hollywood, Butch Cassidy and the Sundance Kid is particularly memorable for a long, drawn-out chase scene where ultimately nothing substantive happens.

Springer eBooks, Mar 1, 2005

Lecture Notes in Computer Science, 2003

Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this... more Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliographie; detailed bibliographic data is available in the Internet at <http://dnd.ddb.de>.

A general-purpose method to mechanically transfonn system requirements into a provably equivalent... more A general-purpose method to mechanically transfonn system requirements into a provably equivalent model has yet to appeal: Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including sensor networks and autonomous systems. Currently available tools and methods that start with a formul model of a system and mechanically produce a provably equivalent implementation are valuable but not su8cient. The ''gap" unjlled by such tools and methods is that their. formal models cannot be proven to be equivalent to the system requirements as originated by the customel: For the classes of systems whose behavior can be described as ajnite (but significant) set of scenarios, we ofer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations. Automatic code generation from requirements has been the ultimate objective of software engineering almostsince the advent of high-level progfamming languages, calls for a "requirements-based programming" capability have

Kluwer Academic Publishers eBooks, Mar 7, 2006

NASA is studying advanced technologies for a future robotic exploration mission to the asteroid b... more NASA is studying advanced technologies for a future robotic exploration mission to the asteroid belt. This mission, the prospective ANTS (Autonomous Nano Technology Swarm) mission, will comprise of 1,000 autonomous robotic agents designed to cooperate in asteroid exploration. The emergent properties of swarm type missions make them powerful, but at the same time are more difficult to design and assure that the proper behaviors will emerge. We are currently investigating formal methods and techniques for verification and validation of future swarm-based missions. The advantage of using formal methods is their ability to mathematically assure the behavior of a swarm, emergent or otherwise. The ANT mission is being used as an example and case study for swarm-based missions for which to experiment and test current formal methods with intelligent swarms. Using the ANTS mission, we have evaluated multiple formal methods to determine their effectiveness in modeling and assuring swarm behavior.

Increasingly, NASA relies on autonomous systems concepts, not only in the mission control centers... more Increasingly, NASA relies on autonomous systems concepts, not only in the mission control centers on the ground, but also on spacecraft and on rovers and other assets on extraterrestrial bodies to achieve the full range of advanced mission objectives. While autonomy cost-effectively supports mission goals, autonomicity supports survivability of remote missions, especially when human tending is not feasible. Analysis of two prototype NASA agent-based systems and of a proposed mission involving numerous cooperating spacecraft illustrates how autonomous and autonomic system concepts may be brought to bear on future space missions

NASA monographs in systems and software engineering, 2010

transmitted, in any form or by any means, with the prior permission in writing of the publishers,... more transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licenses issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. The use of registered names, trademarks, etc., in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made.

NASA monographs in systems and software engineering, 2009

Having focused on automation and autonomy in space-based systems in the previous chapter, attenti... more Having focused on automation and autonomy in space-based systems in the previous chapter, attention is now directed toward ground-based systems, particularly the automation of spacecraft control centers. We describe a strategy for automating NASA ground-based systems by using a multiagent system to support ground-based autonomous satellite-subsystem monitoring and report generation supporting mission operations. Over the last several years, work has

NASA is studying advanced technologies for a future robotic exploration mission to the asteroid b... more NASA is studying advanced technologies for a future robotic exploration mission to the asteroid belt. This mission, the prospective ANTS (Autonomous Nano Technology Swarm) mission, will comprise of 1,000 autonomous robotic agents designed to cooperate in asteroid exploration. The emergent properties of swarm type missions make them powerful, but at the same time are more dflcult to design and assure that the proper behaviors will emerge. We are currently investigating formal methods and techniques for verification and validation of future swarm-based missions. The advantage of using formal methods is their ability to mathematically assure the behavior of a swarm, emergent or otherwise. The ANT mission is being used as an example and case study for swarm-based missions for which to experiment and test current formal methods with intelligent swam. Using the ANTS mission, we have evaluated multiple formal methods to determine their effectiveness in modeling and assuring swarm behavior.

NASA monographs in systems and software engineering, 2009

In this chapter, we discuss the application of the autonomy technologies considered in previous c... more In this chapter, we discuss the application of the autonomy technologies considered in previous chapters to spacecraft constellations. The needs of constellations that can be supported by onboard autonomy are described along with the enhancements attainable by constellation missions through the application of onboard autonomy. A list of hypothetical constellation mission types is also posed and a list of governance concepts is then presented in relation to the degree of central control being exercised on the constellation. Finally, the chapter discusses mobile agent concepts to support autonomic constellations.

Springer eBooks, 2009

In this chapter, we examine how agent technology might be utilized in flight software (FSW) to en... more In this chapter, we examine how agent technology might be utilized in flight software (FSW) to enable increased levels of autonomy in spacecraft missions. Again, as stated in the Preface, our discussion relates exclusively to uncrewed assets (robotic spacecraft, instrument platforms on planetary bodies, robotic rovers, etc.) or assets that must be capable of untended operations (e.g., ground stations during

Springer eBooks, Oct 10, 2009

Having focused on automation and autonomy in space-based systems in the previous chapter, attenti... more Having focused on automation and autonomy in space-based systems in the previous chapter, attention is now directed toward ground-based systems, particularly the automation of spacecraft control centers. We describe a strategy for automating NASA ground-based systems by using a multiagent system to support ground-based autonomous satellite-subsystem monitoring and report generation supporting mission operations. Over the last several years, work has progressed on developing prototypes of agent-based control centers [2, 36, 86, 134]. With the prototypes has come an improved understanding of the potentials for autonomous ground-based command and control activities that could be realized from the innovative use of agent technologies. Three of the prototypes will be described: Agent-based Flight Operations Associate (AFLOAT), Lights Out Ground Operations System (LOGOS), and Agent Concept Testbed (ACT).

NASA is investigating new paradigms for future space exploration, heavily focused on the (still) ... more NASA is investigating new paradigms for future space exploration, heavily focused on the (still) emerging technologies of autonomous and autonomic systems [47, 48, 49]. Missions that rely on multiple, smaller, collaborating spacecraft, analogous to swarms in nature, are being investigated to supplement and complement traditional missions that rely on one large spacecraft [16]. The small spacecraft in such missions would each be able to operate on their own to accomplish a part of a mission, but would need to interact and exchange information with the other spacecraft to successfully execute the mission. This new systems paradigm offers several advantages: • the ability to explore environments and regions in space where traditional craft would be impractical,

The problem of maintaining a desired number of mobile agents on a network is not trivial, especia... more The problem of maintaining a desired number of mobile agents on a network is not trivial, especially if we want a completely decentralized solution. Decentralized control makes a system more r e bust and less susceptible to partial failures. The problem is exacerbated on wireless ad hoc networks where host mobility can result in significant changes in the network size and topology. In this paper we propose an ecology-inspired approach to the management of the number of agents. The approach associates agents with living organisms and tasks with food. Agents procreate or die based on the abundance of uncompleted tasks (food). We performed a series of experiments investigating p r o p erties of such systems and analyzed their stability under various conditions. We concluded that the ecology based metaphor can be successfully applied to the management of agent populations on wireless ad hoc networks. 3 Problem Formulation 3.1 Motivation In a typical dynamic ad hoc network there is limited, variable bandwidth between hosts, and the memory and CPU on each host is constrained. Given this dynamic and resource constrained environment, it is impractical to prescribe any precomputed solution. The solution we propose for such networks is to create a system that can control the number of agents dynamically, adapting to the ever-changing environment. In order to work in the context of an agent based system, a control system should be distributed and decentralized. By distributed, we mean that the system should be able to use the underlying network to parallelize problem solving on multiple hosts. By decentralized, we mean that the system should avoid reliance on a single node, and should allow each agent to act independently. The emergent behavior resulting from the individual localized control decisions ideally will yield an optimal, or near-optimal, solution at the global level. 3.2 Approach Large ecosystems usually have several attractive qualities (such as dynamic decentralized control, self regulation, no single point of failure, robustness, and stability) that we require for our system. We propose a solution to the problem of determining the number of agents appropriate for a task at hand that is inspired by large ecosystems: 1. Each task in our system is associated with food. 2. Agents which successfully complete a task collect the associated food points. 3. Agents consume food points over time to sustain their existence. 4. Agents that exhaust their supply of food die. 5. An abundance of food can cause a new agent to spawn. I " All of these techniques promise to improve on the current research and provide a more stable decentralized ways to control the number of agents on a wireless ad hoc network. 5.2 Conclusions This paper developed an ecology-based model for managing the number of agents on ad hoc wireless networks. We have discovered that an ecosystem based model can provide decentralized distributed robust control of agents in dynamic and uncertain network environments. Our approach involves a novel exploitation of properties of ad hoc networks, enabling mobile agents to automatically adapt to changes that affect their communication and migration. The capability to dynamically adjust to the state of their network provides new possibilities for stable MAS.

NASA monographs in systems and software engineering, 2017

Casimir interactions play an important role in the dynamics of nanoscale objects. Here, we invest... more Casimir interactions play an important role in the dynamics of nanoscale objects. Here, we investigate the noncontact transfer of angular momentum at the nanoscale through the analysis of the Casimir torque acting on a chain of rotating nanoparticles. We show that this interaction, which arises from the vacuum and thermal fluctuations of the electromagnetic field, enables an efficient transfer of angular momentum between the elements of the chain. Working within the framework of fluctuational electrodynamics, we derive analytical expressions for the Casimir torque acting on each nanoparticle in the chain, which we use to study the synchronization of chains with different geometries and to predict unexpected dynamics, including a "rattleback"-like behavior. Our results provide insights into the Casimir torque and how it can be exploited to achieve efficient noncontact transfer of angular momentum at the nanoscale, and therefore have important implications for the control and manipulation of nanomechanical devices.

NASA monographs in systems and software engineering, 2017

Unlike our first topic, attitude, orbit is a word for which most people probably could conjure up... more Unlike our first topic, attitude, orbit is a word for which most people probably could conjure up a reasonable visual image. They might envision the Earth and the other planets circling the Sun, or the Moon or a spacecraft circling the Earth.

NASA monographs in systems and software engineering, 2017

In addition to reviving the classic “buddy picture” genre, as well as making Paul Newman and Robe... more In addition to reviving the classic “buddy picture” genre, as well as making Paul Newman and Robert Redford two of the top box office draws in Hollywood, Butch Cassidy and the Sundance Kid is particularly memorable for a long, drawn-out chase scene where ultimately nothing substantive happens.

Springer eBooks, Mar 1, 2005

Lecture Notes in Computer Science, 2003

Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this... more Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliographie; detailed bibliographic data is available in the Internet at <http://dnd.ddb.de>.

A general-purpose method to mechanically transfonn system requirements into a provably equivalent... more A general-purpose method to mechanically transfonn system requirements into a provably equivalent model has yet to appeal: Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including sensor networks and autonomous systems. Currently available tools and methods that start with a formul model of a system and mechanically produce a provably equivalent implementation are valuable but not su8cient. The ''gap" unjlled by such tools and methods is that their. formal models cannot be proven to be equivalent to the system requirements as originated by the customel: For the classes of systems whose behavior can be described as ajnite (but significant) set of scenarios, we ofer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations. Automatic code generation from requirements has been the ultimate objective of software engineering almostsince the advent of high-level progfamming languages, calls for a "requirements-based programming" capability have

Kluwer Academic Publishers eBooks, Mar 7, 2006

NASA is studying advanced technologies for a future robotic exploration mission to the asteroid b... more NASA is studying advanced technologies for a future robotic exploration mission to the asteroid belt. This mission, the prospective ANTS (Autonomous Nano Technology Swarm) mission, will comprise of 1,000 autonomous robotic agents designed to cooperate in asteroid exploration. The emergent properties of swarm type missions make them powerful, but at the same time are more difficult to design and assure that the proper behaviors will emerge. We are currently investigating formal methods and techniques for verification and validation of future swarm-based missions. The advantage of using formal methods is their ability to mathematically assure the behavior of a swarm, emergent or otherwise. The ANT mission is being used as an example and case study for swarm-based missions for which to experiment and test current formal methods with intelligent swarms. Using the ANTS mission, we have evaluated multiple formal methods to determine their effectiveness in modeling and assuring swarm behavior.

Increasingly, NASA relies on autonomous systems concepts, not only in the mission control centers... more Increasingly, NASA relies on autonomous systems concepts, not only in the mission control centers on the ground, but also on spacecraft and on rovers and other assets on extraterrestrial bodies to achieve the full range of advanced mission objectives. While autonomy cost-effectively supports mission goals, autonomicity supports survivability of remote missions, especially when human tending is not feasible. Analysis of two prototype NASA agent-based systems and of a proposed mission involving numerous cooperating spacecraft illustrates how autonomous and autonomic system concepts may be brought to bear on future space missions

NASA monographs in systems and software engineering, 2010

transmitted, in any form or by any means, with the prior permission in writing of the publishers,... more transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licenses issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. The use of registered names, trademarks, etc., in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made.