Navigation of a mobile robot using mono-vision and mono-audition

Incorporation of various types of sensors increases the degrees of autonomy and intelligence of mobile robots (mobots) in perceiving surroundings, which at the same time imposes a large computational burden on data processing. The purpose of the research presented in this paper is to develop a low-cost multisensor system and incidental algorithms for autonomous navigation of a mobot. This paper proposes digital image processing schemes for map-building and localization of a mobot using a monocular vision system and a single ultrasonic sensor in indoor environments. In localization, the camera calibration is preceded so that the depth information can be acquired from the image obtained by a single camera. For map-building, fast and effective image processing techniques based on morphology are applied to reduce computational complexities. For preliminary experiments, we have integrated a mobot system whose main components are a mono-vision system, a single ultrasonic sensor, and a notebook PC, mounted on a mobile base. The proposed algorithms were implemented, and the mobot was able to localize itself in an allowed position error range and to locate dynamic obstacles moving reasonably fast inside a building. The overall results demonstrate the suitability of the proposed methods for developing autonomous service mobots in indoor environments.