When a ship sails with the yawing of prolonged periodicity, its fuel consumption is said to increase by several percentage or more than when it sails without such yawing. The conventional autopilot systems have the weather adjusting deadband which is manually adjusted by the operator to avoid high frequency disturbance in rough seas. However, the increase in the deadband leads to the decrease in low frequency performance and eventually to the yawing of prolonged periodicity. Our new autopilot system which employs DDC is aimed to solve the problems inherent in the conventional autopilot systems and offers the following advantages. 1. The high frequency component of gyro signal is filtered by Kalman filter, and the stable rudder control is secured without increasing the deadband. 2. The function to estimate the wave condition from the gyro signal is added. 3. According to the various conditions such as cargo load, ship speed, and estimated wave condition, this system automatically selects the optimum control gain and filter parameters given in advance. It is evident from the computer simulation that this system is far more capable of minimizing the yawing under various ship conditions as compared with the conventional autopilot systems. At the present time, this system is actually being used on board a 230 KDWT tanker. The field data to substantiate the above-mentioned advantages are expected in near future.

  • Supplemental Notes:
    • Proceedings Fifth Ship Control Systems Symposium, David W. Taylor Naval Ship Research and Development Center, Annapolis, Maryland, October 30-November 3, 1978, Volume 4.
  • Corporate Authors:

    David Taylor Naval Ship R&D Center

    Bethesda, MD  United States  20084
  • Authors:
    • Sugimoto, A
    • Kojima, T
  • Publication Date: 1978

Media Info

  • Features: References;
  • Pagination: 13 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00187950
  • Record Type: Publication
  • Source Agency: David Taylor Naval Ship R&D Center
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Feb 3 1979 12:00AM