Remote operated vehicle tether disturbances analysis and target tracking control

In order to realize accurate target tracking for remote operated vehicle, this study has analyzed the tension force from the tether and model based dynamic control strategy. For precise control, the tether effects have been analyzed through a partial differential equation. Each element of the tether has been taken as an elastic body, and the tether has been divided into two parts: in the air and in the sea water, waves and current disturbances have been taken into consideration. Based on the dynamic model of ROV, a backstepping sliding mode controller has been established in order to improve the controller´s systematic robustness against disturbances. Theoretical analysis proves that the solutions are ultimately bounded using the proposed controller. Tank experiments with and without current disturbances have been performed including the depth control, heading control and pipeline tracking. The efficacy and superiority of the backstepping sliding mode control have been verified. It is confirmed the analysis and the controller can meet the request for target tracking control.