深空探测器在轨推力器参数辨识方法

Parameter identification method of thruster in orbit for deep space probe

针对中国首次自主火星探测任务需要,结合环绕器质量特性和推进系统布局构型,分析了喷气卸载对整器角动量的影响。在分析的基础上,通过飞轮卸载前后三轴转速变化规律,计算整器角动量变化情况,并解算出每次喷气时产生的冲量及推力方向偏差;通过同组推力器作用时对各轴的扰动,解算整器质心坐标。利用在轨数据分析了天问一号探测器巡航段6次使用不同推力器的喷气卸载情况,解算的推力器方向偏差、质心坐标和地面设计值进行比对,实测推力方向偏差不超过0.6°,质心绝对偏差小于18mm,验证了计算方法的有效性和正确性,可作为后续轨控任务的点火方向制定、燃料预算的输入依据。

According to the needs of China's first autonomous Mars exploration mission,combined with the mass characteristics of the orbiter and the layout of the propulsion system,the influence of jet unloading on the angular momentum of the detector was analyzed.On the basis of the analysis,the angular momentum variation of the detector was calculated by the change law of the rotating speed of three axes before and after the flywheel unloading,and the impulse generated during each jet was solved,as well as the thrust direction deviation.Coordinates of the detector's center of mass were solved through disturbance of each axis from the thrusters within the same group.The jet unloading of China's Mars probe Tianwen-1 in its cruise phase using different thrusters for six times was analyzed with in-orbit data.Calculation results of the thrust vector deviation and the centroid coordinates were highly consistent with design values.The measured thrust vector deviation was not more than 0.6,and the absolute deviation of the center of mass was less than 18mm,proving that the calculation method was effective and correct which can be used to set the direction of ignition and propellant budget in subsequent orbital control tasks.