Effect of Seeker Disturbance Rejection Rate Parasitic Loop on Line of Sight Rate Extraction.

To choose a reasonable line of sight rate extraction scheme of seeker in missile general design, a useful method is present based on analysis of characteristics of seeker disturbance rejection rate parasitic loop. A model of parasitic loop were established for a typical gimbaled seeker. Then using frequency domain methods the characteristic difference of disturbance rejection rate transfer function and parasitic loop as well as guidance system are analyzed for two kinds of extraction scheme. The effect of guidance parameters on the parasitic loop stability region is studied with Routh criteria. Using an infrared image seeker's parameters, simulation is done under typical flight condition to confirm the theoretical analysis. The study shows that the parasitic loop can change characteristics of guidance system, and line of sight rate extraction schemes also have essential effect on stability and stable performance of guidance system due to parasitic loop. To identify characteristics of seeker disturbance rejection rate is useful for determining line of sight rate extraction scheme. [ABSTRACT FROM AUTHOR]