Text mining for robotic action ontology engineering

Abstract

The development of the action ontology (ACAT) from domain specific texts allows to discover previously unknown dependencies between robotic actions and their environment objects. This study explains the conceptual model of the ontology actions and environment objects and relations between them. Two main ACAT ontology classes determine the hierarchical structure of action and object hyponymy/hypernymy, troponyny: „action“ and „object“. Each action and object synset contains a subset of synonymous entities. All synsets from the ontology are described by the semantic roles, used in action execution by robots: main action, main object, primary object and secondary object. Study also explores various text mining methods for action ontology learning: collocation extraction, frequency lists, bag-of-words, word space model and Heart’s hyponomy recognition patterns. Verbnet thematic roles and frames are used to identify text syntactic and semantic structure – in this way recognized new text patterns allow to define dependencies between ontology synsets. Robotic action classes are identified by text classification with SVM machine learning method, where action categories are treated as classes, and appropriate verb context – as classification instances. The action ontology completeness and utility is evaluated empirically, by running as additional source of knowledge base in instruction processing system. This study introduces the preliminary testing results of the ACAT ontology usage in instruction processing to sequence of robotic execution tasks (chosen rotor assembly and biotechnology laboratory scenarios). While the explicit knowledge is parsed directly from the instructions, reasoning on queried ACAT ontology data allows to cover instruction tacit knowledge. It helps to execute human readable instructions with polysemous information, omissions, too general or non-robotic actions and not relevant textsSistemų analizės katedraTaikomosios informatikos katedraVytauto Didžiojo universiteta