Parameterization of H{sub}∞-Suboptimal Ship Autopilot Pid Controller

摘要

Course keeping controller synthesis for displacement ship is considered. To deal with a time invariant plant the time-scaled model of ship yawing is used. Desired spectral properties of the control signal are met by using H{sub}∞-criteria, withweighting functions appropriately chosen. It is shown that the solution of this problem has a structure of PID controller followed by a low-pass filter of the second order if the open-loop system has been approximated by the rational function of the third order. It is also shown that the controller obtained depends on the only parameter --Nyquist frequency of the open-loop system. The advantages of this representation are that controller has a simple structure, its coefficients can be easily adjusted, the good phase margin is ensured.