The Research For Lift-feedback Fin Stabilizer System And The Method Of Fin Stabilizer Variable-Structure Control

The research for ship-stabilized technology has experienced nearly one hundred years. More than three hundred and fifty kinds of stabilizers have been produced during the length of time. Among them,fin stabilizer is the most effective equipment. Fin stabilizer is a kind of active stabilizer,which is designed on the principle of torque counteraction.Fin stabilizer applied at present is an angle feedback system which calculate the controlling torque through the fin angle. Because the relationship between the lift produced by fin and the fin angle is mainly determined by the hydrodynamic experiment,so there are some defects. Big error exists in the hydrodynamic experiment,especially on dynamic state;it is more difficult to test the hydrodynamic property of fin stabilizer. So the lift comes from this kind of control method can't counteract the wave torque perfectly,thereby affecting the stabilizer's function. If we can obtain the lift produced by the fin stabilizer directly,we would avoid many indefinite factors when fin angle transferred into lift. This is the principle of lift-feedback fin stabilizer system. This task is the core constructive item of national " 211 project". The ultimate result is to equip lift-feedback fin stabilizer experiment equipment in laboratory.The work concerned are listed as follows:1. Properly rebuild the experiment formwork of lift-feedback fin stabilizer system on the base of original angle-feedback fin stabilizer system.2. Using embedded industry control computer,rebuild the controlling and steering part of fin stabilizer,substitute the former simulating parts and realize the digital in the control part.3. Design,install and test the lift sensor of the lift feedback part,and test the lift signal.4. Make the further research in control method in the angle feedback finstabilizer system. Using sliding mode variable-structure control method to design controller,carry on stimulating and make contrast with the traditional PID in order to justify its superiority in stabilized effects. The above-mentioned achievements not only bear theoretical value,but alsobuild the solid foundation for the further research of lift-feedback fin stabilizersystem.