A Trajectory Calculus for Qualitative Spatial Reasoning Using Answer Set Programming. Issue 3 (10th August 2018)

• Record Type: Journal Article
• Authors: BARYANNIS, GEORGE; TACHMAZIDIS, ILIAS; BATSAKIS, SOTIRIS; ANTONIOU, GRIGORIS; ALVIANO, MARIO; SELLIS, TIMOS; TSAI, PEI-WEI
• Editors: Dal Palu, Alessandro; Tarau, Paul
• Is Part Of: Theory and practice of logic programming. Volume 18:Issue 3/4(2018)
• Page Start: 355
• Page End: 371
• Publication Date: 2018-08-10
• Subjects: Answer Set Programming, -- Spatial Reasoning, -- Qualitative Reasoning, -- Trajectory; Logic programming -- Periodicals; Artificial intelligence -- Computer programs -- Periodicals; Constraint programming (Computer science) -- Periodicals; 005.115
• DOI: 10.1017/S147106841800011X
• Languages: English
• ISSNs: 1471-0684

Abstract

Abstract: Spatial information is often expressed using qualitative terms such as natural language expressions instead of coordinates; reasoning over such terms has several practical applications, such as bus routes planning. Representing and reasoning on trajectories is a specific case of qualitative spatial reasoning that focuses on moving objects and their paths. In this work, we propose two versions of a trajectory calculus based on the allowed properties over trajectories, where trajectories are defined as a sequence of non-overlapping regions of a partitioned map. More specifically, if a given trajectory is allowed to start and finish at the same region, 6 base relations are defined (TC-6). If a given trajectory should have different start and finish regions but cycles are allowed within, 10 base relations are defined (TC-10). Both versions of the calculus are implemented as ASP programs; we propose several different encodings, including a generalised program capable of encoding any qualitative calculus in ASP. All proposed encodings are experimentally evaluated using a real-world dataset. Experiment results show that the best performing implementation can scale up to an input of 250 trajectories for TC-6 and 150 trajectories for TC-10 for the problem of discovering a consistent configuration, a significant improvement compared to previous ASP implementations for similar qualitative spatial and temporal calculi.