Research On Relative Target Motion Tracking And Accurate Position Control Of Surface Ship

Marine salvage is hot in the field of marine technology. During the salvage, it's necessary that the rescue ship should close enough to the target ship, which is a high requirement to the operation of the vessel. There is great safety potential risk in the orthodox marine salvage, because the rescue is conducted after crew operating the vessel near to the target. This paper connected with the practical requirements which based on the rescue for a wrecked marine ship, the move tracing and accurate position controlling of the relative targets were researched. The research contents are as follows:First, the mathematical model of rescue ship and float moving model of wrecked ship were built in this paper. Focus on the main environmental influences, which impact the float moving for the wrecked ship, the wind, wave and flow mathematical models were built respectively, and the validities of these models were verified via simulating.Second, recording to the requirements during a surface rescue, the position between the two ship should be controlled and the trace of the wrecked ship should be kept, the measurement of omnibearing relative position at a short range for the surface rescue should be achieved under a certain harsh condition, the measuring scheme based on miniRadaScan micro-wave reference system was proposed and designed the resolving methods for the relative distance and relative heading direction. Taking into account the safeguard requirements of keeping a relative position and tracing dynamically between the secure and wrecked ship in a close distance, the strategy that making the tracing process piecewise was introduced to attain the safe and effective, in addition, it has been verified by simulation.Third, aiming at the features that, during a secure, only under the condition that secure and ship keeping an accurate position controlling, can the safe operation be realized. The longitudinal, lateral position and bow direction controllers were designed separately by adopting fuzzy self-adaptive PID algorithm, and the tracing of relative moving and accurate position control under harsh ocean condition were attained by adjusting PID parameters online. The verifications of the tracing effect, measurement scheme and tracing strategy were completed via simulations.Finally, in order to verify the strategy and method for the relative moving and accurate position controlling between the rescue and the wrecked ship, a system which simulate the moving and tracing control was constructed, attain the control for target tracing by the simulation system which looks the all-round moving vehicle as the target ship, float moving for the wrecked vessel was simulated by a hand-control vehicle with five degree of freedom,attain the practical measurement for the target moving via relative position measuring equipment which based on miniRadaScan Sensor and Responder, then developed the interface display, parameters setting, plant choosing, parameters adjusting, operation mode choosing,experimental data memory modules. The effectiveness and practicability of the proposed measurement scheme, tracing strategy, fuzzy based PID controller with three degree of freedom were verified via the relative position controlling and tracing control simulation experiment.