Dynamics and control of a towed vehicle in transient mode

The dynamics and control of a lowed vehicle when it changes depth and course were studied theoretically and experimentally. A mathematical model of motions of the vehicle is described in 6-degree-freedom motion equations and that of the towing cable is done using the lumped mass model. Control systems based on an optimal control theory (LQI synthesis) were developed to control the vehicle safely during the depth change. In the course change experiment the PID controller was used. The performance of the controller and the accuracy of the mathematical model of motions have been evaluated by field experiments. The towing tension was also measured in field experiments to confirm the safety of the towing cable.