Robotic mapping of building interior - Precision analysis

Autonomous map-making of building interiors is becoming a widely used tool in robotics for various applications. One of the major problems to be dealt with in the development of this tool is the precision of the coordinates obtained in the process of mapping. Previous developments in map-making focused on the empirical examination of the accuracies. This paper presents an analysis of the precision of a map created by a robotic arm of 6 articulated degrees of freedom mounted on a mobile carriage and utilizing a laser beam range-finder for horizontal and vertical rotational scanning. The analysis shows that two parameters are the main factors affecting the precision of the map: (1) orientation of the carriage on which the robot is mounted and (2) distance between the sensor and the walls being scanned. It was found that if the carriage location accuracy is 1 cm, then in order to achieve coordinate precision not worse than 3cm: (1) the carriage orientation accuracy must be at least 0.1° and (2) the distance between the sensor and the walls being scanned should not exceed 3m.