脉冲星导航可靠、稳定、精度高,是实现火星探测器自主导航的有效手段之一.针对脉冲星导航中脉冲到达时间的微小误差会引起巨大的位置估计误差这一问题,提出了一种基于扩维Unsented卡尔曼滤波(ASUKF,Augmented State Unscented Kalman Filter)的火星探测器脉冲星自主导航方法,建立了以位置、速度和脉冲到达时间的常值测量误差作为状态量的导航系统数学模型,可在对探测器位置、速度进行估计的同时有效估计并修正脉冲到达时间的常值测量误差,并降低随机测量误差的影响.仿真结果表明该方法的导航定位精度可达350 m以内,可以满足火星探测自主导航的需要.
Autonomous navigation using pulsars is characterized by its steady,credible performance,high navigation accuracy,which is suitable for mars probe.Because errors in photons time of arrival reduce location accuracy,a kind of pulsars navigation method based on ASUKF(augmented state unscented Kalman filter) was presented.System models using position,velocity and constant error in time of arrival as state parameters were built.The method could not only estimate and correct the constant error in photons time of arrival,but reduce the influence of random error as well.Simulations show that a estimated position error within 350m is obtained,which demonstrates this method can satisfy the requirements of Mars exploration.