Agents
LEXSYS: Architecture and Implication for Intelligent Agent systems
LEXSYS, (Legume Expert System) was a project conceived at IITA (International Institute of Tropical Agriculture) Ibadan Nigeria. It was initiated by the COMBS (Collaborative Group on Maize-Based Systems Research in the 1990. It was meant for a general framework for characterizing on-farm testing for technology design for sustainable cereal-based cropping system. LEXSYS is not a true expert system as the name would imply, but simply a user-friendly information system. This work is an attempt to give a formal representation of the existing system and then present areas where intelligent agent can be applied.
Investigating Output Accuracy for a Discrete Event Simulation Model and an Agent Based Simulation Model
Majid, Mazlina Abdul, Aickelin, Uwe, Siebers, Peer-Olaf
In this paper, we investigate output accuracy for a Discrete Event Simulation (DES) model and Agent Based Simulation (ABS) model. The purpose of this investigation is to find out which of these simulation techniques is the best one for modelling human reactive behaviour in the retail sector. In order to study the output accuracy in both models, we have carried out a validation experiment in which we compared the results from our simulation models to the performance of a real system. Our experiment was carried out using a large UK department store as a case study. We had to determine an efficient implementation of management policy in the store's fitting room using DES and ABS. Overall, we have found that both simulation models were a good representation of the real system when modelling human reactive behaviour.
Learning Temporal Plans from Observation of Human Collaborative Behavior
Chernova, Sonia (MIT Media Lab) | Breazeal, Cynthia (MIT Media Lab)
The objective of our research effort is to enable robots to engage in complex collaborative tasks with human-robot interaction. To function as a reliable assistant or teammate, the robot must be able to adapt to the actions of its human partner and respond to temporal variations in its own and its partner's actions. Dynamic plan execution algorithms provide a fast and robust method of executing collaborative multi-robot tasks in the presence of temporal uncertainty. However, current state of the art algorithms, rely on hand-crafted plans, providing no means of generating plans for new tasks. In this paper, we outline our approach for learning a model of collaborative robot behavior by observing human-human interaction of the target task. Through statistical analysis of the recorded human behavior we extract patterns of common behavior, and use the resulting model to learn a temporal plan. The result is a learning framework that automatically produces temporal plans for use with dynamic planning that model human collaborative behavior and produce human-like behavior in the robot. In this paper, we present our current progress in the development of this learning framework.
Actor-Critic Policy Learning in Cooperative Planning
Redding, Joshua (Massachusetts Institute of Technology) | Geramifard, Alborz (Massachusetts Institute of Technology) | How, Jonathan (Massachusetts Institute of Technology)
In this paper, we introduce a method for learning and adapting cooperative control strategies in real-time stochastic domains. Our framework is an instance of the intelligent cooperative control architecture (iCCA). The agent starts by following the "safe" plan calculated by the planning module and incrementally adapting the policy to maximize rewards. Actor-critic and consensus-based bundle algorithm (CBBA) were employed as the building blocks of the iCCA framework. We demonstrate the performance of our approach by simulating limited fuel unmanned aerial vehicles aiming for stochastic targets. The integrated framework boosted the optimality of the solution by 10 percent compared to running each of the modules individually.
The Immediate Present Train Model Time Production and Representation for Cognitive Agents
Snaider, Javier (The University of Memphis) | McCall, Ryan (The University of Memphis) | Franklin, Stan (The University of Memphis)
Time perception and inferences there from are of critical importance to many autonomous agents. But time is not perceived directly by any sensory organ. We argue that time is constructed by cognitive processes. Here we present a model for time perception that concentrates on succession and duration, and that generates these concepts and others, such as continuity, immediate present duration, and lengths of time. These concepts are grounded through the perceptual process itself. The LIDA cognitive model is used to illustrate these ideas.
Dynamic Execution of Temporal Plans for Temporally Fluid Human-Robot Teaming
Shah, Julie A. (Massachusetts Institute of Technology) | Williams, Brian C. (Massachusetts Institute of Technology) | Breazeal, Cynthia (Massachusetts Institute of Technology)
Introducing robots as teammates in medical, space, and military domains raises interesting and challenging human factors issues that do not necessarily arise in multi-robot coordination. For example, we must consider how to design robots that integrate seamlessly with human group dynamics. An essential quality of a good human partner is her ability to robustly anticipate and adapt to other team members and the environment. Robots should preserve this ability and avoid constraining their human partners’ flexibility to act. This requires that the robot partner be capable of reasoning quickly online, and adapting to the humans’ actions in a temporally fluid way. This paper describes recent advances in dynamic plan execution, and argues that these advances provide a potentially powerful framework for explicitly modeling and efficiently reasoning on temporal information for human-robot interaction. We describe an executive named Chaski that enables a robot to coordinate with a human to execute a shared plan under different models of teamwork. We have applied Chaski to demonstrate teamwork using two Barrett Whole Arm Manipulators, and describe our ongoing work to demonstrate temporally fluid human-robot teaming using the Mobile-Dexterous-Social (MDS) robot.
Anticipation in Human-Robot Interaction
Hoffman, Guy (Georgia Tech Center for Music Technology)
Anticipating the actions of others is key to coordinating joint activities. We propose the notion of anticipatory action and perception for for robots acting with humans. We describe four systems in which anticipation has been modeled for human-robot interaction; two in a teamwork setting, and two in a human-robot joint performance setting. In evaluating the effects of anticipatory agent activity, we find in one study that anticipation aids in team efficiency, as well as in the perceived commitment of the robot to the team and its contribution to the team's fluency and success. In another study we see anticipatory action and perception affect the human partner's sense of team fluency, the team's improvement over time, the robot’s contribution to the efficiency and fluency, the robot's intelligence, and the robot’s adaptation to the task. We also find that subjects working with the anticipatory robot attribute more human qualities to the robot, such as gender and intelligence.
Exploring the Implications of Time in Discrete Event Social Simulations
Alt, Jonathan (Naval Postgraduate School) | Lieberman, Stephen (Naval Postgraduate School) | Rowaei, Ahmed Al (Naval Postgraduate School)
Representing human behavior and cognition, from individuals to societies, presents a range of challenges to the modeling and simulation community. A common thread through many of these challenges is formulating an authentic representation of time. Many of the issues related to time representation, from the sequencing of cognitive decision processes and information processing, to communication and interaction between agents, to the longer term time scales associated with ideas such as belief revision, remain open research areas throughout the community. The inherent variability between human subjects makes generalization difficult even with data from designed experiments. Discrete event simulation (DES) provides a well-documented alternative to time-step simulation and shows potential for applications across the domain of human behavior representation. This paper provides an overview of a modular discrete event framework for social simulation, along with the social and behavioral theories underlying the currently implemented modules. We discuss the practical challenges presented by time in the representation of human cognition, and provide a case study analysis of the output of the discrete event social simulation.
Stream-Based Middleware Support for Embedded Reasoning
Heintz, Fredrik (Linköping University) | Kvarnström, Jonas (Linköping University) | Doherty, Patrick (Linköping University)
For autonomous systems such as unmanned aerial vehicles tosuccessfully perform complex missions, a great deal of embedded reasoning is required at varying levels of abstraction. In order to make use of diverse reasoning modules in such systems, issues ofintegration such as sensor data flow and information flow between such modules has to be taken into account. The DyKnow framework is a tool with a formal basis that pragmatically deals with many of the architectural issues which arise in such systems. This includes a systematic stream-based method for handling the sense-reasoning gap,caused by the wide difference in abstraction levels between the noisy data generally available from sensors and the symbolic, semantically meaningful information required by many high-level reasoning modules. DyKnow has proven to be quite robust and widely applicable to different aspects of hybrid software architectures forrobotics. In this paper, we describe the DyKnow framework and show how it is integrated and used in unmanned aerial vehicle systems developed in our group. In particular, we focus on issues pertaining to the sense-reasoning gap and the symbol grounding problem and the use of DyKnow as a means of generating semantic structures representing situational awareness for such systems. We also discuss the use of DyKnow in the context of automated planning, in particular execution monitoring.
Golog.lua: Towards a Non-Prolog Implementation of Golog for Embedded Systems
Ferrein, Alexander (University of Cape Town)
Among many approaches to address the high-level decision making problem for autonomous robots and agents, the robot programming and plan language Golog follows a logic-based deliberative approach, and its successors were successfully deployed in a number of robotics applications over the past ten years. Usually, Golog interpreter are implemented in Prolog, which is not available for our target platform, the bi-ped robot platform Nao. In this paper we sketch our novel prototype implementation of a Golog interpreter in the scripting language Lua. With the example of the elevator domain we discuss how the basic action theory is specified and how we implemented fluent regression or backtracking in Lua. One possible advantage of the availability of a Non-Prolog implementation of Golog could be that Golog becomes available on a larger number of platforms, and also becomes more attractive for roboticists outside the Cognitive Robotics community.