Online Task Merging with a Hierarchical Hybrid Task Planner for Mobile Service Robots

Sebastian Stock, Masoumeh Mansouri, Federico Pecora, Joachim Hertzberg

In: Proceedings of the 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2015). IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS-15) September 28-October 2 Hamburg Germany Seiten 6459-6464 ISBN 978-1-4799-9994-1 IEEE 2015.


Plan-based robot control has to consider a multitude of aspects of tasks at once, such as task dependency, time, space, and resource usage. Hybrid planning is a strategy for treating them jointly. However, by incorporating all these aspects into a hybrid planner, its search space is huge by construction. This paper introduces the planner CHIMP, which is based on meta-CSP planning to represent the hybrid plan space and uses hierarchical planning as the strategy for cutting efficiently through this space. The paper makes two contributions: First, it describes how HTN planning is integrated into meta-CSP reasoning leading to a planner that can reason about different forms of knowledge and that is fast enough to be used on a robot. Second, it demonstrates CHIMP's task merging capabilities, i.e., the unification of different tasks from different plan parts, resulting in plans that are more efficient to execute. It also allows to merge new tasks online into a plan that is being executed. This is demonstrated on a PR2 robot.

Deutsches Forschungszentrum für Künstliche Intelligenz
German Research Center for Artificial Intelligence