变质量飞行器变轨中摇摆发动机指向跟踪问题研究

针对携带大推力摇摆式轨控发动机的变质量飞行器，研究了其推力方向跟踪质心位置变化同时指向惯性空间推进方向的问题。研究中将飞行器分为可摇摆的发动机和变质量的平台两部分，利用雷诺迁移定理和变质量力学原理建立了整个变质量系统的数学模型；在控制系统设计中，通过一组线性转换，将系统转换为摄动双积分系统，以时间最优为性能指标，利用相平面法构造开关控制律。仿真结果表明，变质量飞行器利用该控制律能够实现摇摆发动机在惯性空间中跟踪质心位置变化的同时与推进方向保持一致。

Thrust Pointing Tracking for the Variable-Mass Vehicle with the Swiveling Engine during the Orbit Transfer

A research is presented to solve the problem that the thrust vector of swiveling engine on a variable-mass vehicle not only should track changes of centroid position but also should point to a direction in inertial space. In this paper, the variable-mass vehicle is considered to be consisted of two parts—an engine and a variable-mass platform; meanwhile the mathematical model of the complex variable-mass system is established by using the Reynolds Migration Theorem. Besides, the dynamics system is converted into a perturbed double-integral system by means of a linear transformation in the control system design. The time optimal on-off control law is designed on the phase plane formed by Euler angle error and angular velocity error. Simulation results demonstrate the performance of the control law used for the variable-mass vehicle.