The loosely coupled integration system using a Pseudolite Ultrasonic System and a Dead-reckoning for the autonomous mobile robots localization

In this paper, a loosely coupled integration system is proposed for improving the positioning performance of a mobile robot by fusing the Pseudolite Ultrasonic System (PUS), which is an absolute position measurement system using direct ultrasonic wave, with the odometer of Dead-Reckoning (DR). The PUS and the DR calculate position independently and a Kalman filter estimates the position using position information from the PUS and the DR. To estimate the position of the mobile robot accurately in case the LOS (line-of-sight) between ultrasonic transmitter and receiver is blocked due to obstacles, a positioning failure detection algorithm is proposed. The positioning performances of the proposed loosely coupled integrated system are verified and evaluated by experiments. The experimental results show that the position of mobile robot is estimated accurately by the proposed algorithm.