The meaning of spatial words can only be evaluated by establishing a reference to the properties of the environment in which the word is used. For example, in order to evaluate what is to the left of something or how fast is fast in a given context, we need to evaluate properties such as the position of objects in the scene, their typical function and behaviour, the size of the scene and the perspective from which the scene is viewed. Rather than encoding the semantic rules that define spatial expressions by hand, we developed a system where such rules are learned from descriptions produced by human commentators and information that a mobile robot has about itself and its environment. We concentrate on two scenarios and words that are used in them. In the first scenario, the robot is moving in an enclosed space and the descriptions refer to its motion (“You’re going forward slowly” and “Now you’re turning right”). In the second scenario, the robot is static in an enclosed space which contains real-size objects such as desks, chairs and walls. Here we are primarily interested in prepositional phrases that describe relationships between objects (“The chair is to the left of you” and “The table is further away than the chair”). The perspective can be varied by changing the location of the robot. Following the learning stage, which is performed offline, the system is able to use this domain specific knowledge to generate new descriptions in new environments or to “understand” these expressions by providing feedback to the user, either linguistically or by performing motion actions. If a robot can be taught to “understand” and use such expressions in a manner that would seem natural to a human observer, then we can be reasonably sure that we have captured at least something important about their semantics. Two kinds of evaluation were performed. First, the performance of machine learning classifiers was evaluated on independent test sets using 10-fold cross-validation. A comparison of classifier performance (in ...
Teaching mobile robots to use spatial words
2018-10-04
Theses
Electronic Resource
English
DDC: | 629 |
A Versatile Kit for Teaching Intelligent Mobile Robots
Springer Verlag | 2011
|A Versatile Kit for Teaching Intelligent Mobile Robots
British Library Conference Proceedings | 2011
|Springer Verlag | 2018
|NTIS | 1986
|