The simulation and model of twisted lever-arm effect in transfer-alignment of strapdown inertial navigation
Based on the theory of twisted lever-arm effect, this paper provided a new model for the lever-arm effect caused by the shipboard weapons' transfer-alignment, not considering the dynamic twist. Deflection angle of the second-order Markov process model was established and set up in simulink. Composed with the non-twisted lever-arm effect, the result showed that the acceleration error caused by dynamic twist was large and need compensated.
Self-calibration method of the inner lever-arm parameters for a tri-axis RINS
A rotational inertial navigation system (RINS) could improve navigation performance by modulating the inertial sensor errors with rotatable gimbals. When an inertial measurement unit (IMU) rotates, the deviations between the accelerometer-sensitive points and the IMU center will lead to an inner lever-arm effect. In this paper, a self-calibration method of the inner lever-arm parameters for a tri-axis RINS is proposed. A novel rotation scheme with variable angular rate rotation is designed to motivate the velocity errors caused by the inner lever-arm effect. By extending all inner lever-arm parameters as filter states, a Kalman filter with velocity errors as measurement is established to achieve the calibration. The accuracy and feasibility of the proposed method are illustrated by both simulations and experiments. The final results indicate that the inner lever-arm effect is significantly restrained after compensation by the calibration results.
What is Enlightenment
Enlightenment is man's emergence from his self-imposed nonage. Nonage is the inability to use one's own understanding without another's guidance. This nonage is self-imposed if its cause lies not in lack of understanding but in indecision and lack of courage to use one's own mind without another's guidance. Dare to know! (Sapere aude.) "Have the courage to use your own understanding," is therefore the motto of the enlightenment.