Study on Compensation Strategy for Interference Torque in Roll-pitch Seeker

This paper analyses the fundamental reason of interference torque on pitch frame derived from the rotating roll frame which is introduced through mechanical calculation and simulation. In order to keep the stable working of the pitch frame, corresponding compensation scheme is built to offset the interference torque resulting from installation error. Mechanics analysis is made in a noninertial coordinate system and calculation simulation is carried out. Considering the dynamic character of rotating roll frame and the model of the motor, accurate compensation control command on pitch motor is applied on the pitch control loop. After a series of theoretical deducibility, simulation verification event is carried out on a roll-pitch seeker. Real-time angular velocity and angular acceleration of the pitch gimbal should be measured, and some key parameters such as distance and angular of installation error in noninertial coordinate system should be measured before compensation design. In this case, the scheme calculates a specific compensation control command matching the roll-pitch seeker and the compensation can eliminate the disadvantage influence of the installation error. The comparison of pitch frame behaviors between operating results before and after the compensation control command proves the feasibility and effectiveness of the proposed method.