单框架控制力矩陀螺输出特性分析

广泛用于航天领域的单框架控制力矩陀螺, 具有力矩放大效应的优点,其理论基础为有假设条件的力矩放大原理. 本文不局限于这些假设, 不限定工况,解析单框架控制力矩陀螺的输出特性. 考虑安装基座的运动,得到具有两维输入三维输出的单框架控制力矩陀螺力矩输出模型,提出将输出力矩分解为可调控与不可调控两部分. 为分析单框架控制力矩陀螺的输出特性,定义两个参数, 分别为输出输入力矩比和输出力矩利用率. 研究发现,单框架控制力矩陀螺不恒有力矩放大效应, 也不恒有高效的力矩利用率,两者与其状态密切相关. 最后,以含两个单框架控制力矩陀螺的航天器姿态机动任务为例,对非对角奇异鲁棒操纵控制和优化控制进行仿真,检验了单框架控制力矩陀螺输出特性对控制效果的影响. 同时,根据单框架控制力矩陀螺的三维输出特性, 借助一个单框架控制力矩陀螺的优化控制,实现了航天器的三轴姿态机动. 仿真结果显示, 在优化控制过程中,单框架控制力矩陀螺始终具有力矩放大效应和高效的力矩利用率. 

OUTPUT CHARACTERISTIC ANALYSIS OF SINGLE GIMBAL CONTROL MOMENT GYROSCOPE

The single-gimbal control moment gyroscope (SCMG), which is widely used in aerospace field, has the advantage of torque amplification effect. It is based on the principle of torque amplification with some hypotheses. In this paper, the output characteristics of SCMG are analyzed without those hypotheses. By considering the motion of the mounting base, the output torque model of SCMG with a two-dimensional input and three-dimensional output is obtained, in which the adjustable and nonadjustable parts are identified. In order to analyze the output characteristics of SCMG, two parameters are defined. One is the ratio of the norms about the SCMG's output to input torque vectors. The other is the ratio of the norm about the SCMG's used and unused torque vector, which is to represent the utilization ratio of the SCMG's output torque. In all feasible regions, the results show that the characteristic parameters of torque output are is not always greater than 1, i.e., SCMG does not always has torque amplification effect and efficient torque utilization, which are closely related to the state of SCMG. Finally, for the spacecraft attitude maneuver task with two SCMGs, the simulation of non-diagonal singular robust control and optimal control is completed. It is found that the control effect is closely related to the output characteristic parameters which are determined by the system state. At the same time, the optimal control with a SCMG is used to realize the three-dimensional attitude maneuver of a spacecraft based on the three-dimensional output characteristics of SCMG. The simulation results show that the SCMG always has the torque amplification effect and the efficient torque utilization in the process of optimal control.