Stability region analysis of the parasitic loop of the semi-strapdown homing seeker

Abstract

The stability of the parasitic loop induced by the disturbance rejection effect (DRE) of a semi-strapdown homing seeker (SSHS) is analysed in this paper. First, the seeker’s tracking controller is designed so as to have a simple structure and then the explicit relationships between the control parameters and the desired performance index is presented. Mathematical models of the DRE of the SSHS and the parasitic loop are then proposed. The approximate maximum magnitude of the seeker’s DRE as a function of the friction coefficient and the counter electromotive force coefficient is also given. Routh’s criterion is used to obtain the approximate stability region of the parasitic loop. The necessary and sufficient conditions which ensure the stability of the parasitic loop are directly related to the seeker’s control parameters. This approach provides direct theoretical support for the design of a seeker’s control system. Simulations are performed to verify the validity of the stability analysis performed on the parasitic loop.

Research on the Influence of the Disturbance Rejection Rate of a Roll–Pitch Seeker on Stable Tracking Characteristics

“…The guidance information output error caused by the attitude movement and interference torque can be expressed by the DRR, which is usually defined as the ratio of the extra line-of-sight rate of the optical axis caused by vehicle attitude interference to attitude disturbance velocity. As a fixed characteristic of the roll-pitch seeker, the DRR will affect the guidance accuracy of the aircraft by coupling to form a parasitic loop on the guidance circuit [16][17][18].…”

Study on Parasite Effect with Strapdown Seeker in Consideration of Time Delay

“…First, some researchers have been putting their effort to investigate effects of the scale factor errors on a terminal homing guidance loop [1][2][3][4]. With this approach, the stability regions of the parasite loop, involving the strapdown homing seeker, were analyzed in several studies [5][6][7][8]. As the second research direction, some efforts have also been made to devise new homing guidance laws, corresponding terminal homing guidance loops [9][10][11], and guidance filters for the strapdown seeker [12][13][14].…”

Influence of Seeker Disturbance Rejection and Radome Error on the Lyapunov Stability of Guidance Systems

“…The disturbance rejection rate is the transfer function which represents the incorrect angular rate caused by an attitude disturbance applied to the missile's body [18]. Therefore, this study …”