Effect of seeker disturbance rejection performance on the control system stability

Due to the imperfect disturbance rejection performance, missile motion may severely degrade the seeker tracking accuracy. In this paper, the process of the missile body angular motion acting on seeker servo platform is analyzed, the model of parasitical loop of seeker disturbance rejection is constructed, and the conception of seeker disturbance rejection with phase lag is present. Through simulation, the stability zone of system with respect to disturbance rejection rate is plotted, and the effect of disturbance rejection rate phase lag on system stability is analyzed. The study results give a constructive advice about how to choose the key parameters of the missile guidance and control system. The conclusion of this paper is helpful for the engineers of missile during the preliminary design period.