Analysis And Control Of Reduction Of Cargo Pendulation On Crane Ships

Crane ships are not only the important tools to transfer cargos from ships to ships,but also of great use in building ports, shipbuilding engineerings, building bridges,rescuing work underwater and other kinds of ocean engineerings. The wave-inducedmotion of the crane ship produces large pendulation of hoisted cargo and causesoperation to be suspended.This work is to study the pendulation of hoisted cargo and design the controlsystem.The objective of this work is to use the concept of delayed-position feedbackto develop a control system to reduce pendulation of hoisted cargo on ship-mountedcranes to such an extent that cargo transfer could take place in sea states where theseoperations are now not possible.1. The wave-induced motion of the crane ship coupled with the motion of hoistedcargo, which makes it too complicated to analyze the dynamics of hoisted payload.Regardless of its impact on ship, this work assumes the motion of suspension pointknown and regards it as the base excitation. Firstly, the cable-payload assembly ismodeled as a spherical pendulum. Then we derive nonlinear equations set, within-plane motion coupled with out-plane motion. Consequently, we research theprobability that base excitation results in most critical scenario and the dynamicresponse. Finally, we get a positive conclusion.2. This work introduces the delayed-position feedback, and analyzes the stabilityof the response. Consequently, we apply the method to the cable-payload assembly toreduce the pendulation of cargo.3. According to the delayed-position feedback, a controller is developed underthe demand of the pendulation of cargo.4. To verify the effectiveness of the controller, numerical simulation based onT-ACS is given. The result demonstrates that the amplitude can be significantlyreduced in the controlled system.In this work, we get the nonlinear equations set after dynamic analysis ofcable-payload system. In order to reduce the pendulation, we develop a successfulcontrol strategy based on delayed-position feedback. The simulation resultsdemonstrate that the pendulation can be significantly reduced. Therefore, the strategyis of great use in engineering if it'll be put into practice.