微纳卫星固体火箭推进器推力矢量测量方法

尽管固体火箭推进器应用于微纳卫星平台拥有诸多优点,但此类小型固体火箭推进器推力矢量难以测量。对此,提出一种利用惯性传感器量测值映射推力矢量大小的方法,开展地面动态飞行实验。首先,基于牛顿欧拉法和变质量系统理论建立地面实验系统的动力学模型,分析卫星的动力学与运动学特性;然后,构建惯性测量单元(inertial measurement unit, IMU)的量测方程,结合系统动力学中推力矢量与惯性传感器量测值间的映射关系,推导推力矢量测量模型;最后,通过仿真分析影响推力矢量测量精度的误差来源,并对惯性传感器的安装构型进行优化设计。通过数值仿真实验,在优化设计后,该测量方法可保证主推力和侧向推力测量精度均优于0.3%。

Thrust vector measurement method of micro-nano satellite solid rocket thruster

Solid rocket thruster has many advantages when applied to micro-nano satellites, but the thrust vector of such a kind of small solid rocket thruster is difficult to measure. A method for mapping the thrust vector by using the inertial sensor measurement value through the ground dynamic flight test is proposed to solve the problem. Firstly, the dynamics model of the ground test system is established by the Newton-Euler method and the variable mass theory, and the dynamics and kinematics characteristics of the satellite are analysed. Then the measurement equation of the inertial measurement unit (IMU) is constructed, and the thrust measurement model is deduced by the mapping relationship between the thrust vector and the measurement value of the inertial sensor. Finally, the error sources affecting the measurement accuracy of the thrust vector are analyzed by simulations, and the installation configuration of the inertial sensor is optimized. Through numerical simulation experiments, the measurement method after optimization can ensure that the measurement accuracy of the main thrust and the lateral thrust is better than 0.3%.