850 likes | 1.02k Views
Pedro Mitsuo Shiroma Advisor : Mario F. M. Campos Co-advisor: Vijay Kumar. CoMutaR : An approach for task allocation. Motivation. In a near future it is very likely that several robots will be present in the same workspace. Motivation. In this scenario we will have:
E N D
Pedro Mitsuo Shiroma Advisor: Mario F. M. Campos Co-advisor: Vijay Kumar CoMutaR: An approach for task allocation
Motivation In a near future it is very likely that several robots will be present in the same workspace
Motivation In this scenario we will have: • Robots executing theirs assigned tasks, • with rich sensorial capacity, • high processing power, • and communication devices; • A lot of underutilized resources; • Increasingly large amounts of continuously gathered data;
Problem definition How to effectively allocate the available resources (whole robots, sensors, gathered data, actuators, processing power, etc.) for the successful execution of multiple tasks? or, more formally…
Problem definition Given a set of (possibly) heterogeneous mobile robots located in a dynamical environment and a set of tasks that need to be executed, allocate tasks to one or more robots efficiently.
Task1 Task2 Task3 Task4 ... Taskp Problem definition robot1 robot2 robot3 ... robotm
Outline • Related work • CoMutaR • Experimental results • Conclusion
Outline • Related work • CoMutaR • Experimental results • Conclusion
Related Work: Taxonomy • Tasks • Robots • Assignment [Gerkey 2003]
Related Work: Taxonomy – Tasks • SR – Single-Robot tasks • MR – Multi-Robot tasks robot1 Task1 robot2 Task2 robot3
Related Work: Taxonomy – Assignment • No knowledge • Model-based Task1 Task2 t t0 t1 Task1 t2 Task2 t
Related Work: Taxonomy – Robots • ST – Single-Task Robot • MT – Multi-Task Robot robot1 Task1 robot2 Task2 Task3
Related work “'Most commonly, task allocation problems assume robots are single-task robots, since more capable robots that perform multiple tasks in parallel are still beyond the current state of the art” Lynne E. Parker, Springer handbook of robotics (2008)
Outline • Related work • CoMutaR • Overview • Action • Share-restricted resource • Constraint functions • Query • Coalition • Experimental results • Conclusion
CoMutaR: Overview • Coalition of actions Obstacle avoidance
open auction open query open query cost cost bid winner connect CoMutaR: Overview • Coalition formation • Protocol (IA) Obstacle avoidance Obstacle avoidance t connect
CoMutaR: Overview • Assumptions • Tasks can be subdivided into actions; • Actions are able to determine or estimate, based on the query, its constraint functions; • If all inputs (queries) and constraint functions are obeyed then the action will successfully perform as expected.
CoMutaR: Nomenclature robot • : the 4th action in robot 3; • : the 2nd share-restricted resource in robot 1 • : the constraint function imposed by over action Share-restricted resource
Outline • Related work • CoMutaR • Overview • Action • Share-restricted resource • Constraint functions • Query • Coalition • Experimental results • Conclusion
CoMutaR: Action • An action is any computational module that can either produce data or perform a task robot1 Task1
CoMutaR: Action • Sensor reading: • Data transform: • Task accomplishing: Task
Outline • Related work • CoMutaR • Overview • Action • Share-restricted resource • Constraint functions • Query • Coalition • Experimental results • Conclusion
CoMutaR: Share-restricted resource • MT (Multitasking) robots Task1 robot1 Task2
CoMutaR: Share-restricted resource • A share-restricted resource is any property that cannot be freely shared among actions. • Communication link; • Processing power; • Power supply; • Allowed configuration space;
CoMutaR: Share-restricted resource • Codomain; • Communication link: • Processing power: • Power supply: • Allowed c-space: configuration space
CoMutaR: Share-restricted resource • Maximum capacity: • Communication link: maximum bandwidth; • Processing power: allocated processing time; • Power supply: battery capacity; • Allowed c-space;
CoMutaR: Share-restricted resource – Allowed c-space composition surveillance controller
Outline • Related work • CoMutaR • Overview • Action • Share-restricted resource • Constraint functions • Query • Coalition • Experimental results • Conclusion
CoMutaR: Constraint function ... ... ... ... ... . . . ... ...
CoMutaR: Constraint function • Constraint function: • compound operator: • comparison operator:
CoMutaR: Constraint function – Communication link • codomain: • : required communication bandwidth • : maximum bandwidth • 30Mb/s + 20Mb/s ≤ 100Mb/s
CoMutaR: Constraint function – Processing power • codomain: • : required processing time • : allocated processing power • 10% + 20% ≤ 90%
CoMutaR: Constraint function – Allowed c-space • Allowed c-space Obstacle avoider Non-holonomic constraint composition
CoMutaR: Constraint function – Allowed c-space • Constraints imposed by sensors (queries) Queries are periodically updated
CoMutaR: Constraint function – Allowed c-space • Potential field approaches: • Lower potential: • Allowed • Greater potential: • Not allowed
CoMutaR: Constraint function – Allowed c-space • codomain: • : empty space
Outline • Related work • CoMutaR • Overview • Action • Share-restricted resource • Constraint functions • Query • Coalition • Experimental results • Conclusion
CoMutaR: Query • Information type [Donald1997]: • Resource database [Cowley2004]: • Query:
CoMutaR: Query • Dynamical environments: • Reactive tasks: • Mapping: • User interface:
CoMutaR: Query • Independence of producer and consumer allows fault tolerance: Obstacle avoidance roboti robotj
CoMutaR: Query • An action can execute only if all input queries are answerable; • A query is a contract between producer and consumer, which guarantee data connection; • A query can include other queries: • A surveillance action is taking snapshots: • A pursue action in the same robot is trying to track an intruder:
CoMutaR: Query • An action can intervene on the query of another action: • An obstacle avoidance is querying for obstacles: • A box pushing action can alter the region queried by the obstacle avoidance:
Outline • Related work • CoMutaR • Overview • Action • Share-restricted resource • Constraint functions • Query • Coalition • Experimental results • Conclusion
CoMutaR: Coalition formation protocol action2 action1 Task1 db1 db2 actionn
Outline • Related work • CoMutaR • Experimental results • Conclusion
Tightly-coupled tasks – Box pushing • Vleft • vright