Fusion of data from ultrasonic LPS and isolated beacons for improving MR navigation

This paper presents an improved navigation system for Mobile Robots (MR) in extensive areas using different Ultrasonic Local Positioning Systems (ULPS) and the complement of Isolated Beacons (IB) in regions without LPS coverage. Each single LPS has a high accuracy in positioning but a limited coverage area. The proposal of this paper is the use of a set of additional Isolated Beacons to cover areas between LPSs and then reducing the number of them needed. When the MR is on a place where the positioning data from the ULPS is available, it can obtain its position with high accuracy. On the other hand, if the MR is outside of a LPS coverage area it can measure the distance to one of the IBs and fuse this information with the one of the MR odometer using an H-infinity filter to estimate its position. The complete system has been tested in some scenarios with simulated data and the results show the improvement of the MR navigation error when the IBs are used.