**5. SLAM using range sonar array**

In the past decades, SLAM (Simultaneous Localization and Mapping) has been one of most hot issues in the robotics community (Leonard & Burrant-Whyte, 1992; Castellanos & Tardos, 1999; Thrun et al., 2005). SLAM problems arise when the robot does not have access to a map of the environment; nor does it have access to its own poses (Thrun et al., 2005).

Development of a Hovering-Type Intelligent Autonomous Underwater Vehicle, P-SURO 33

same point through its rotation, in other word, there is a drift for the vehicle's position in the rotating mode. So, though the accuracy of range sonar measurement is in the centimetres level, the total position error for this kind of rotation mode is significant. Through a number

Consider this kind of forward/backward motion; the vehicle's forward/backward velocity can be calculated using range sonar measurements. For this purpose, the following filter is

where ��� and �� denote each of filtered and raw measurements of range sonar, and � is

���(�) = (1−2��)���(�−1) + 2����(�), (6)

of basin tests, we observe that this kind of position error is up to 0.5m.

designed for acquisition of range sonar raw measurements

filtering order. The filtering results can be seen in Fig. 14.

Fig. 14. Calculated forward speeds.

Fig. 15. Comparison of heading measurements

Fig. 12. Acquisition of 2D profile image.

Fig. 13. Acquisition of 3D profile image.
