Robots providing services to human users in personal context are known as personal service robots. Enriching and facilitating people's lives are their general missions. Acquisition of spatial representations is therefore crucial for such a robot to move around in a human-shared environment, provide services and interact with the user about the environment. With methods developed in the field of autonomous exploration it is possible for a mobile robot to build a metric representation from sensor data, while exploring an initially unknown environment. However, due to the limited perceptual...