考虑飞轮动态特性的卫星平台控制策略与成像性能分析

发布时间：2018-01-09 07:34

本文关键词：考虑飞轮动态特性的卫星平台控制策略与成像性能分析　出处：《北京理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：航天光学遥感卫星在拍照过程中,卫星平台振动会使曝光时间内拍摄物影像与感光介质之间存在相对运动,产生像移,从而导致成像模糊。因此如何实现卫星平台的高精度高稳定控制以及建立合理有效的成像性能分析评价指标具有实际的工程指导意义。本文在此背景下,首先对带有挠性附件的卫星平台建立了基于Kane方法的动力学模型,并且考虑了角动量装置反作用飞轮在实际运转过程中的摩擦效应和静动不平衡产生的振动现象。建立的飞轮摩擦模型,分别对比了Stribeck静态模型、Dahl动态模型和LuGre动态模型的动态特性,本文采用LuGre模型能更加全面描述实际的摩擦行为。静动不平衡采用等效质量块的方法,描述了不平衡力矩振动频率与飞轮转速相关。其次对带有飞轮的卫星平台设计了不依赖系统精确建模参数的强鲁棒性的自抗扰控制器,通过跟踪微分器(TD)、扩张状态观测器(ESO)及非线性状态误差反馈控制律(NLSEF)分别实现对信号的快速无超调跟踪、干扰的动态补偿及控制力矩的输出。同时为了改善控制增益参数,借鉴了模糊控制思想,提出了模糊整定的方法。并且实验仿真给出了改进前后的对比,验证了模糊整定具有更好的控制效果。最后将调制传递函数(MTF)作为光学载荷成像性能分析指标,理论分析了横向振动对MTF的影响。仿真给出了卫星平台振动对成像系统的像移和MTF性能影响分析,得出模糊自抗扰控制(FADRC)具有更好的成像性能的结论。
[Abstract]:In the process of taking pictures of space optical remote sensing satellite, the vibration of the satellite platform will cause the relative motion between the image and the photosensitive medium during the exposure time, resulting in the image shift. Therefore, how to achieve high precision and high stability control of satellite platform and establish reasonable and effective imaging performance analysis evaluation index has practical engineering significance. Firstly, a dynamic model based on Kane method is established for the satellite platform with flexible appendages. The friction effect of the reaction flywheel of angular momentum device and the vibration phenomenon caused by static and dynamic imbalance are considered. The friction model of flywheel is established and the Stribeck static model is compared respectively. The dynamic characteristics of Dahl dynamic model and LuGre dynamic model are discussed in this paper. In this paper, the LuGre model is used to describe the actual friction behavior more comprehensively, and the equivalent mass block method is used in the static and dynamic unbalance. The unbalance moment vibration frequency is related to the speed of the flywheel. Secondly, an active disturbance rejection controller is designed for the satellite platform with flywheel, which does not depend on the precise modeling parameters of the system. Tracking signal without overshoot is realized by tracking differentiator, extended state observer (ESO) and nonlinear state error feedback control law (NLSEF). The dynamic compensation of disturbance and the output of control torque. In order to improve the control gain parameters, the fuzzy tuning method is put forward in order to improve the control gain parameters, and the comparison before and after the improvement is given in the experimental simulation. Finally, the modulation transfer function (MTF) is used as the optical load imaging performance analysis index. The influence of lateral vibration on MTF is analyzed theoretically, and the influence of satellite platform vibration on image shift and MTF performance of imaging system is analyzed by simulation. It is concluded that FADRC has better imaging performance.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V448.2

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