Individual Plans from Team Plans using Petri Nets
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Transcript of Individual Plans from Team Plans using Petri Nets
SYSC 5103-Software Agents Nov 22, 2005
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Individual Plans from Team Plans using Petri Nets
• Afiya Kassim-100307450• [email protected]
• Presentation based on paper: From Team Plan to Individual Plans: a Petri Net-based Approach, Bonnet-Torres and Tessier, in AAMAS’05, Netherlands, pg 797-804, 2005.
SYSC 5103-Software Agents Nov 22, 2005
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Outline
• Introduction• Notion of Agenticity• Team Plans• Abstracting the Team Plan• Example • Conclusion
SYSC 5103-Software Agents Nov 22, 2005
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Introduction
• Motivation: Team planning is a difficult problem
• Framework for representing a team plan • Projection of team plan on individual
agents• This paper addresses the notion of
activity planning using petri-nets
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Agenticity Hierarchy
Agenticity Hierarchy(depth of the agent in the hierarchy)
Agents implemented to carry out the mission are organized hierarchically in a
team
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Degree of an Agent
• Degree is the largest agenticity of the individual agents that belong to this agent
• An elementary agent has a degree of zero
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Goals
• An elementary goal is one such that there is a specification of the course of actions to be performed by an agent(composite or individual), resulting in the achievement of the goal
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Team Plan
• A team plan is designed in terms of a detailed sequence of tasks, represented as a petri-net
Source(Introduction of agents) and Sink(Removal of agents)
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Rules for Abstracting the Team Plan
Reduction of Late Arrival
• Preserves the level of agenticity• Token is modified to encompass the newly introduced agent
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Rules Cont’d
Reduction of Early Withdrawal
• Preserves the level of agenticity• Token is modified
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Rules Cont’d
Fusion of Consecutive Activities
• Transposition of the substitution rule for consecutive places in ordinary Petri nets• Preserves the level of agenticity• Token is not modified
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Rules Cont’d
Fusion of Choice Between Activities
• Preserves the level of agenticity• Token is modified to bear the different possible agenticity sub-hierarchies• Agent is tagged showing there are multiple possible organising structures
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Rules Cont’d
Fusion of Parallel Activities
• Derived from the implicit place suppression rule in ordinary Petri nets• Decreases the level of agenticity• Token is modified
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Rules Cont’d
Reduction of Agent Transfer
• Preserves the level of agenticity• Tokens are modified• Pt is split rule 1 and rule 2 is then applied on the two separate branches
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Conclusion
• No discussion on team plan creation• How tokens are created or modified?• Future work: Handling re-planning within
the team in the event of a failure or an external action