Co-ordination and Co-operation Between CGF Agents Dr Jeremy Baxter Parallel and Distributed Simulation Group S&P Sector, Malvern

Overview of Presentation zBackground zCo-ordination and Co-operation problems zTechniques from Multi-Agent Systems –Joint Intentions theory. –Four step model zExample implementation –Squadron (Company) assault

Background z“Broad Agents” based CGF system –Military command and control structure –Independent Agents and behaviours for each level –Breaks up responsibilities and behaviours Troop Commander Command and Control Intelligence Higher Level Objective Squadron Commander Troop Commander Troop Commander Tank Lower Level Objectives

Initial Co-ordination Problems zComplex composite behaviours –Initial timing by message passing –Prone to programming bugs –Context lost if commander died zWeak model of group context –produced separately from orders to subordinates –developer responsible for linking group and sub-group states

Generic Problems and Solutions zExisting CGF systems have problems –Lack of co-operative group behaviour –Co-ordination is inflexible and prone to failure –Composite behaviours are therefore weak and brittle zSolutions from Multi Agent Systems literature –Provide a framework for group behaviour –Model the context for re-planning decisions –Model agents’ responsibilities to their group and the operator

Joint Intentions Theory zA logic based model of what it means to co-operate on a task –Explicitly represents roles and commitments –Improves robustness zKey elements –Mutual belief (I know he knows I know …..) –Mutual goals and plans –Commitment to informing other agents zExample:- Traffic convoys

Definitions zWeak Goal EITHER Goal to achieve P OR P has been achieved AND Goal to inform group P is achieved OR P is unachievable AND Goal to inform group P unachievable zWeak Mutual Goal Mutual belief that everyone has a Weak Goal to achieve P zJoint Persistent Goal Mutual belief that P has not yet been achieved AND Mutual goal to achieve P AND UNTIL Mutual belief that P is achieved, unachievable or irrelevant A Weak Mutual Goal to achieve P will persist

Definitions 2 zJoint Intention To have a Joint Persistent Goal to do an action while mutually believing that all involved are doing the action –A ‘Group State’ committing all involved both to the goal, a to a way of achieving it and conventions on how to deal with problems zKey elements –Establishing mutual belief in an action –Commitment to informing others

Using Joint Intentions zAttack Helicopter CGF (Tambe et al in STOW) –Preventing teamwork failures, e.g. loss of Scout Helicopter zCo-ordinating independently designed behaviours –generic support for composite actions zFurther Issues –Need to establish approximation to mutual belief –Ways of establishing team goals, e.g. roles and capabilities –Building up and representing shared goals and plans

Four Step Model zRecognition zTeam Formation –Identifying a group capable of performing the task zPlan Formation –Forming and agreeing on the steps to take. Identifying co-ordination zTeam Action –Forming individual, co-ordinated, plans and failure recovery

Example Composite Behaviour zTank Squadron Assault Involves: –Finding a Fire Support Position to Pin down the Enemy –Finding a Concealed Approach for the Assault Group Enemy Position Fire Support Position Fire Support Axis Assault Approach Assault Group Form Up Point Cover Break Point Fire Support Form Up Point 9 Squadron Current Position

Example Implementation zExplicit Group plans –Templated plans with roles –Clear co-ordination statements zShared Group state –Used for co-ordination and recovery if commander dies zIndividual plans derived from group template –Assigned based on roles and capabilities

A Composite Assault Behaviour

Summary zCo-ordination and co-operation is an important aspect of CGF systems zWithout good representations co-ordination becomes hidden and prone to failures zComposite, composable behaviours will need reliable, generic co-ordination and co-operation techniques zFormal techniques from Multi Agent Systems research can help

Further Work zAdjusting the theory to align with military practice zGeneral solutions to execution problems –e.g. role replacement zOperator involvement –visualisation of co-ordination –commitments to the operator by CGF agents