{"type":"ScholarlyArticle","title":"Trading Plan Cost for Timeliness in Situated Temporal Planning","authors":[{"name":"Shahaf Shperberg","slug":"shahaf-shperberg","given":"Shahaf","family":"Shperberg","affiliation":"Ben-Gurion University , Israel"},{"name":"Andrew Coles","slug":"andrew-coles","given":"Andrew","family":"Coles","affiliation":"King's College London , UK"},{"name":"Erez Karpas","slug":"erez-karpas","given":"Erez","family":"Karpas","affiliation":"Technion , Israel"},{"name":"Eyal Shimony","slug":"eyal-shimony","given":"Eyal","family":"Shimony","affiliation":"Ben-Gurion University , Israel"},{"name":"Wheeler Ruml","slug":"wheeler-ruml","given":"Wheeler","family":"Ruml","affiliation":"University of New Hampshire , USA"}],"abstract":"If a planning agent is considering taking a bus, for example, the time that passes during its planning can affect the feasibility of its plans, as the bus may depart before the agent has found a complete plan. Previous work on this situated temporal planning setting proposed an abstract deliberation scheduling scheme for maximizing the probability of finding a plan that is still feasible at the time it is found. In this paper, we extend the deliberation scheduling approach to address problems in which plans can differ in their cost. Like the planning deadlines, these costs can be uncertain until a complete plan has been found. We show that finding a deliberation policy that minimizes expected cost is PSPACE-hard and that even for known costs and deadlines the optimal solution is a contingent, rather than sequential, schedule. We then analyze special cases of the problem and use these results to propose a greedy scheme that considers both the uncertain deadlines and costs. Our empirical evaluation shows that the greedy scheme performs well in practice on a variety of problems, including some generated from planner search trees.","doi":"10.24963/ijcai.2020/577","url":"https://ijcai.org/proceedings/2020/577","pdf":"https://ijcai.org/proceedings/2020/0577.pdf","markdown":"https://ijcai.org/proceedings/2020/577.md","bibtex":"https://ijcai.org/proceedings/2020/bibtex/577","volume":{"slug":"2020","title":"Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2020","url":"https://ijcai.org/proceedings/2020/","year":2020,"location":"Yokohama","dates":"January 2021 (postponed from 11-17 July 2020)","editors":"Christian Bessiere","isbn":"978-0-9992411-6-5","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2020"},"section":"Planning and Scheduling","track":"Main track","number":577,"pages":{"first":4176,"last":4182},"keywords":["Planning and Scheduling: Temporal and Hybrid planning","Heuristic Search and Game Playing: Meta-Reasoning and Meta-heuristics"],"videos":[{"label":"Video","url":"https://videos.ijcai20.org/25157/file_25157.m3u8","length_sec":299,"provider":"hls"}],"references":[{"position":1,"raw":"[Benton et al., 2012] J. Benton, Amanda Coles, and Andrew Coles. Temporal planning with preferences and time- dependent continuous costs. In ICAPS, page 2-10, 2012.","title":"Temporal planning with preferences and timedependent continuous costs","authors":"J Benton, Amanda Coles, Andrew Coles","year":"2012","venue":"ICAPS","doi":null,"url":null,"internal_url":null},{"position":2,"raw":"[Burns et al., 2013] Ethan Burns, Wheeler Ruml, and Minh Binh Do. Heuristic search when time matters. J. Artif. Intell. Res., 47:697-740, 2013.","title":"Heuristic search when time matters","authors":"Ethan Burns, Wheeler Ruml, Minh Binh Do","year":"2013","venue":"J. Artif. Intell. Res","doi":null,"url":null,"internal_url":null},{"position":3,"raw":"[Cashmore et al., 2018] Michael Cashmore, Andrew Coles, Bence Cserna, Erez Karpas, Daniele Magazzeni, and Wheeler Ruml. Temporal planning while the clock ticks. In ICAPS, pages 39-46, 2018.","title":"Temporal planning while the clock ticks","authors":"Michael Cashmore, Andrew Coles, Bence Cserna, Erez Karpas, Daniele Magazzeni, Wheeler Ruml","year":"2018","venue":"ICAPS","doi":null,"url":null,"internal_url":null},{"position":4,"raw":"[Cserna et al., 2017] Bence Cserna, Wheeler Ruml, and Jeremy Frank. Planning time to think: Metareasoning for on-line planning with durative actions. In ICAPS, pages 56-60, 2017.","title":"Planning time to think: Metareasoning for on-line planning with durative actions","authors":"Bence Cserna, Wheeler Ruml, Jeremy Frank","year":"2017","venue":"ICAPS","doi":null,"url":null,"internal_url":null},{"position":5,"raw":"[Cserna et al., 2018] Bence Cserna, William J. Doyle, Jor- dan S. Ramsdell, and Wheeler Ruml. Avoiding dead ends in real-time heuristic search. In AAAI, pages 1306-1313, 2018.","title":"Avoiding dead ends in real-time heuristic search","authors":"Bence Cserna, William J Doyle, Jordan S Ramsdell, Wheeler Ruml","year":"2018","venue":"AAAI","doi":null,"url":null,"internal_url":null},{"position":6,"raw":"[Dionne et al., 2011] Austin J. Dionne, Jordan Tyler Thayer, and Wheeler Ruml. Deadline-aware search using on-line measures of behavior. In SoCS, pages 39-46, 2011.","title":"Deadline-aware search using on-line measures of behavior","authors":"Austin J Dionne, Jordan Tyler Thayer, Wheeler Ruml","year":"2011","venue":"SoCS","doi":null,"url":null,"internal_url":null},{"position":7,"raw":"[Garey and Johnson, 1979] M. R. Garey and D. S. Johnson. Computers and Intractability, A Guide to the Theory of NP-completeness, page 190.","title":"Computers and Intractability, A Guide to the Theory of NP-completeness","authors":"M R Garey, D S Johnson","year":null,"venue":null,"doi":null,"url":null,"internal_url":null},{"position":8,"raw":"W. H. Freeman and Co., 1979.","title":null,"authors":"W H Freeman, Co","year":"1979","venue":null,"doi":null,"url":null,"internal_url":null},{"position":9,"raw":"[Koenig and Sun, 2009] Sven Koenig and Xiaoxun Sun. Comparing real-time and incremental heuristic search for real-time situated agents. Auton. Agents Multi Agent Syst., 18(3):313-341, 2009.","title":"Comparing real-time and incremental heuristic search for real-time situated agents","authors":"Sun ; Koenig, Sven Koenig, Xiaoxun Sun","year":"2009","venue":"Auton. Agents Multi Agent Syst","doi":null,"url":null,"internal_url":null},{"position":10,"raw":"[Niemueller et al., 2015] Tim Niemueller, Gerhard Lake- meyer, and Alexander Ferrein. The RoboCup Logistics League as a Benchmark for Planning in Robotics. In WS on Planning and Robotics (PlanRob) at ICAPS, 2015.","title":"Tim Niemueller, Gerhard Lakemeyer, and Alexander Ferrein. The RoboCup Logistics League as a Benchmark for Planning in Robotics","authors":"Niemueller","year":"2015","venue":"WS on Planning and Robotics (PlanRob) at ICAPS","doi":null,"url":null,"internal_url":null},{"position":11,"raw":"[Russell and Wefald, 1991] Stuart J. Russell and Eric We- fald. Principles of metareasoning. Artificial Intelligence, 49(1-3):361-395, 1991.","title":"Principles of metareasoning","authors":"J Stuart","year":"1991","venue":"Artificial Intelligence","doi":null,"url":null,"internal_url":null},{"position":12,"raw":"[Sharon et al., 2014] Guni Sharon, Ariel Felner, and Nathan R. Sturtevant. Exponential deepening A* for real-time agent-centered search. In AAAI, pages 871-877, 2014.","title":"Exponential deepening A* for real-time agent-centered search","authors":"Guni Sharon, Ariel Felner, Nathan R Sturtevant","year":"2014","venue":"AAAI","doi":null,"url":null,"internal_url":null},{"position":13,"raw":"[Shperberg et al., 2019] Shahaf S. Shperberg, Andrew Coles, Bence Cserna, Erez Karpas, Wheeler Ruml, and Solomon Eyal Shimony. Allocating planning effort when actions expire. In AAAI, pages 2371-2378, 2019.","title":"Allocating planning effort when actions expire","authors":"S Shahaf, Andrew Shperberg, Bence Coles, Erez Cserna, Wheeler Karpas, Solomon Eyal Ruml, Shimony","year":"2019","venue":"AAAI","doi":null,"url":null,"internal_url":null}],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}