Application of H∞ Control in Rudder/Flap Vector Robust Control for Ship Course

For the parameter uncertainty and the disturbance randomicity that exist in ship course motion, the robust controller of ship course is designed on the base of rudder/flap vector control. The system uncertainty is analyzed, and the choice of weighting functions is discussed chiefly. For the sea wave operating on the ship, its energy-concentrating frequency varies as the encountering angle. For different encountering angles, we design the different weighting functions. For the pole of nominal model existing in imaginary axis, we use the bilinear-transform method to handle it. The method of "2-Riccati" equations is adopted to solve the H^infin controller. The system simulation is given, and the result shows that, compared with the PID controller, this system has a higher course precision, better robust performance. And the research has engineering application value.