Analysis Of The Motion And Study On The Constant-depth Control Of The Deep Sea Towed System

Deep sea towed system (DSTS) is composed of ship, cable and towed vehicle. It is mainly used for the seabed's photographing, the exploration of the sea resource and the search for the immersed objects. It is one of the most important tech in the area of deep sea exploration, because of its vast scope, high efficiency as well as good maneuvering.The development and use of the computer simulation and control tech provides a way of DSTS's research----convenient, reliable and effective. By this way, ideal result would be obtained both in the analysis of motion performance and research of consta- nt-depth control. Also these results will be valuable when DSTS goes to work in the r- eal sea.This passage firstly use lumped mass method when do force analysis for the unit of the dispersed cable. Then the system's motion equations can be established by add- ing the boundary conditions of the ship and towed vehicle. A series of data that could describe the system's motion will be obtained by using numerical analysis methods.Besides, the system's parameters will be discussed carefully to understand their effect to the system. The one-level system and second-level system is taken into acco- unt as well. The second-level's heave compensation is studied in depth for providing a better choice of constant-depth control.Except for the above, the control tactics of the towed vehicle's posture and track is discussed here based on the control theory. The single action from the cable to the towed vehicle and the elevator rudder as well as vertical thruster is considered. The constant-depth control module is designed by the PID method.This passage would help when DSTS is under designing or optimizing.