Development of AUV ‘ISiMI’ and experiments on free running and vision guided underwater docking using one camera

Abstract

A series of free running tests was conducted to investigate the dynamic characteristics of ISiMI and to validate its various functions as a test-bed AUV. These tests included a turning test, a zigzag test, an automatic heading test, a depth control test and a guidance control test. The experimental responses were analyzed and compared with the simulation responses to verify the discrepancies between the two sets of results. This chapter presents a review of our research work on the development of the AUV ISiMI and its performance evaluation, by simulations and experimental tests. First, the design and implementation of ISiMI, including its positioning system in the OEB, will be presented. Second, a series of test results in the basin and a discussion of the results will be presented, with comparisons of the simulated and experimental outputs. Finally, the second generation ISiMI, ISiMI100, a sea-trial version of ISiMI, will be introduced. This chapter also presents a final approach algorithm for underwater docking based on vision-guidance, as well as its experimental realization. Configuration of the vision-guidance system for ISiMI will be described. Next, the image processing method used to discriminate an underwater dock is explained. The arrangement of the lights on the dock and how to estimate the center of the dock from the position of the lights is described. The final approach algorithm guides the AUV from when it reaches a distance of 10-15m away of the dock until it reaches the dock. It generates reference yaw and reference pitch from the estimated center and allows the AUV to track them. Underwater docking experiments are also introduced. The overall system validity was investigated and the final approach algorithm was verified. There was a position where the lights on the dock were outside of the camera viewing range when the AUV was close to the dock. It was expected that the vision-guidance would be invalid in this area. It was also expected that an