There are various procedures of analysing the zig-zag test to obtain steering quality parameters of a ship; from the simplest method of the first-order (K and T) equation to the phase-plane analysis taking into account the higher order parameters and nonlinearity. The basic principle of this kind of analysis is to define a number of parameters of a mathematical model so that it fits with a detected ship motion and rudder movement as closely as possible. This may lead us to a simultaneous equation or some kind of the least square error method or iteration procedure. One difficulty is that, the more the number of parameters to be defined, the more complicated the computation, and hence more error is introduced. This note describes the application of the "visual iteration technique" for the analysis of zig-zag tests. To make the iteration on an analogue computer; adjust the parameters of the mathematical model built in the computer simply by turning a number of knobs whilst keeping an eye on the phase-plane trajectory displayed on a cathode-ray oscilloscope. Some of the results obtained are also indicated.

  • Corporate Authors:

    National Research Council of Canada

    1200 Montreal Road
    Ottawa, Ontario  Canada  K1A 0R6
  • Authors:
    • Nomoto, K
    • Kose, K
  • Publication Date: 1975

Media Info

  • Pagination: n.p.

Subject/Index Terms

Filing Info

  • Accession Number: 00323675
  • Record Type: Publication
  • Source Agency: Stevens Institute of Technology
  • Files: TRIS
  • Created Date: Apr 15 1981 12:00AM