Analysis and adaptive compensation of seeker disturbance torque

As an important parameter affecting the isolation of seeker,disturbance torque had an important effect on guidance system, so it was demanded to reduce the disturbance torque's effect on designing of fast guidance system. According to the nonlinear and nonsteady characteristics of the disturbance torque,modeling errors of stabilized platform and guidance-loop constrains, a control method of disturbance torque adaptive compensation was proposed. The design ideas were as follows: band constraints of disturbance rejection rate obtained from guidance precision analysis, and scroll friction(dominant term of the disturbance torque) was estimated by use of state filtering and a nondestructive dither signal addition on guidance command, then, bandpass filtering and state feedback were used to compensate for unwanted disturbance torque effects. The simulation results show that, the estimation accuracy and rapidity of scroll friction coefficient can meet guidance system's demand under the condition of parameter perturbation, and the adaptive compensation method presented can be applied to more realistic case where cross-coupling effects are important.