Pseudo Youla-Kucera Parameterization for Nonminimum-Phase System: Application to Line-of-Sight Stabilization

The disturbance reduces the pointing accuracy of line-of-sight (LOS) stabilization system. The current Youla-Kucera (YK) parameterization is unstable for the nonminimum-phase LOS stabilization system. This work proposes a novel pseudo Youla-Kucera (PYK) parameterization that is appropriate for the nonminimum-phase system. A rectified controller is presented to correct the undesirable nonminimum-phase characteristics. Of the proposed PYK parameterization, the YK parameterization is a particular instance. For both the minimum-phase and nonminimum-phase systems, the PYK parameterization is appropriate. Since the nonminimum-phase LOS stabilization system has a higher bandwidth than the minimum-phase one, the PYK parameterization delivers stronger disturbance suppression performance, as shown in experiments.