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.
Attitude plus angular rate matching method for shipboard transfer alignment
The transfer alignment methods with measurement parameters are limited by sea condition,so an attitude plus angular rate matching method is put forward.In this paper,the deformation of ship's deck and the constant drift of gyros under three typical sea conditions is estimated using this method with Kalman filter,and the estimate precision is interpreted.The feasibility of the calibration of gyro drift is analyzed in detail as well.Study results show that higher precision and shorter response time with robust is obtained.The calibration of gyro drift is depended on the magnitude of dynamic deformation of ship's deck..
Estimation of dynamic alignment errors in shipboard firecontrol systems
A problem in fire control systems is the estimation of the relative alignment between remotely located target sensor and weapon coordinate frames. This paper describes and analyzes a shipboard system concept for estimating initial misalignments and compensating ships dynamic bending and flexure. The concept uses miniature strapdown inertial sensor assemblies at remote sensor/weapon stations to monitor instantaneous differences in rotational and translational motions. Equations are developed for Kalman filter estimation of alignment and flexure errors using incremental angular displacement and incremental velocity matching measurements. Optimal filter performance predictions are shown graphically for calm and rough sea conditions for both conventional and ring laser gyro inertial sensor assemblies.