Identification of Coupled Mathematical Models for Underwater Vehicles

The paper presents the procedure for identification of coupled mathematical models for underwater vehicles. The procedure is performed with the use of a simple laboratory apparatus that consists of a Webcam placed above the experimental pool. The video recording of the underwater vehicle in motion is then analyzed in order to obtain relative speeds within the camera frame. The experiment uses a simple maneuver which excites the vehicle in all controllable directions (in the horizontal plane). The results have shown that even though the system under observation is nonholonomic, the sway motion occurs due to coupling. This allows for determination of dynamic model in uncontrollable directions. The experimental data also show which terms in a general dynamic model can be omitted when dealing with micro underwater vehicles, in order to preserve the simplicity.