AUTOMATIC STEERING DEVICE

PURPOSE:To enable an automatic steering device to perform optimum weather regulation, by a method wherein, based on the detected value of the yawing motion of a ship hull, a parameter under a marine weather condition is determined, and a noise is estimated so that large or small value of the observation noise of a karman filter corresponds to large or small value of the parameter respectively. CONSTITUTION:An azimuth deviation between a set azimuth psi1 and a bow azimuth psi of a compass 4 is detected by a comparator 8, and the result is fed to a karman filter part 9 togetherwith the furning angular velocity psi' of an angular velocity meter 5 and the steering angle delta of a steering angle indicator 7. The karman filter part 9 finds optimum estimated values psie'' and psi'' of an azimuth deviation psie and furning angular velocity psi' on a basis of these data, a ship speed S, and the marine weather parameter of a parameter computing part 15 to send the estimated values to a regulating part 3. The regulating part 3 finds an instruction steering angle delta* based on these estimated values and aforesaid azimuth deviation psie, and based on the instruction steering angle, a steering device 2 is steered.