Modeling and control of underwater robotic vehicles

Remotely operated, underwater robotic vehicles have become the important tool to explore the secrete life undersea. They are used for various purposes: inspection, recovery, construction, etc. With the increased utilization of remotely operated vehicles in subsea applications, the development of autonomous vehicles becomes highly desirable to enhance operator efficiency. However, engineering problems associated with the high density, nonuniform and unstructured seawater environment, and the nonlinear response of the vehicle make a high degree of autonomy difficult to achieve. The dynamic model of the untethered vehicle is presented, and an adaptive control strategy for such vehicles is described. The robustness of the control system with respect to the nonlinear dynamic behavior and parameter uncertainties is investigated by computer simulation. The results show that the use of the adaptive control system can provide the high performance of the vehicle in the presence of unpredictable changes in the dynamics of the vehicle and its environment.