火星着陆器过渡段飞行组合导航优化仿真

摘要

以火星探测任务为背景,针对着陆器进入、下降及着陆过程中,传统的惯性导航精度受初始位置误差影响大、着陆落点精度低等缺点,充分利用两器间的特高频通信链路,提出环绕器无线电测量以及着陆器自身对火视线测量的组合导航方式,运用扩展卡尔曼滤波对着陆器状态进行估计,达到改善导航精度的目的.理论分析与仿真结果表明:增加两器间无线电辅助测量有助于改善动力学惯性外推误差,抑制发散;环绕器无线电测量/着陆器视线方向测量组合导航可使着陆器过渡段导航精度达到5km.着陆器过渡段导航精度的提高有助于改善后续进入、下降及着陆过程中的惯性导航以及最终着陆点位置精度,为火星探测任务提供参考.%Under the background of Mars exploration program,aiming at those challenges that traditional inertial navigation precision of lander during entry,descent and landing process (EDL) largely depends on initial position errors and landing precision of lander is expected to be increased,a novel integrated navigation research during the transition phase is proposed.This paper takes the advantage of ultra high frequency communication link between orbiter and lander,adopts radio measurements between two probes and line of sight measurement to Mars,then utilizes extended Kalman filter for position estimation.Theory analysis and simulation results indicate that increased radio measurement between two probes can polish up errors caused by dynamics propagation and improve divergence phenomenon.Lander's position precision can be within 5 km under the integrated navigation of radio measurement and line of sight measurement to Mars.Transition phase navigation research can be beneficial for continuous EDL inertial navigation and final landing position precision,which is beneficial for future Mars exploration.