Fusion of the odometer and external position system with different coverage areas

Abstract

This paper presents an Extensive Local Positioning System for mobile robots (MRs) that fuses the information from a mobile robot (MR) internal odometer sensor and the measurements of distances from two external systems: an Ultrasonic Local Positioning System (ULPS) with high accuracy but a short coverage area and a set of WiFi beacons that create a WiFi Local Position System (WLPS) with long coverage area but low accuracy. When the MR navigates on the working area, it continuously obtains its relative position thanks to the internal odometer, and the accumulative errors are avoided fusing the WLPS information. When the robot is on a place where the positioning data from the ULPS are available, the mobile robot can obtain its position with high accuracy. The ULPS and the WLPS have been built and tested experimentally.