基于空间目标异步观测的惯导误差快速确定

Aiming at the problem that large initial state error will affect the convergence rate of inertial navigation error in the inertial/celestial navigation system, assisted by star camera observing limited space target with prior position information, a kind of online fast determination method of inertial navigation error based on asynchronous measurement of target-star angular distance is proposed. Firstly, under the condition that rotation angle of optical axis and field of view of star camera are limited, the scheme of acquiring effective reference information of space target through asynchronous photographic observation is designed. Secondly, on the basis of synchronization processing of asynchronous measurement by exploiting state propagation model of inertial navigation error, nonlinear least square optimization model based on angular distance between target and star is constructed which can avoid influence of optical axis disturbance and installation error. Finally, a two-round iterative optimization method is designed to estimate the position error and velocity error of inertial navigation. Monte Carlo simulation results show that the proposed method can effectively estimate the position error and velocity error of inertial navigation by exploiting the limited observation information of space targets and stars, and can compensate the initial position error by 97.73% and the initial velocity error by 66.25% when the initial position error is about ten kilometers. The computation time of the optimization solution error parameter is 0.0160 s.