充液航天器的鲁棒固定时间终端滑模容错控制

本文以三轴稳定充液航天器为研究背景,在其进行姿态机动控制过程中充分考虑了外部未知干扰、参数不确定、执行器故障和控制输入饱和等因素的影响,提出了一种固定时间终端滑模控制策略.动力学建模过程中,利用粘性球摆等效力学模型模拟液体燃料小幅晃动,通过拉格朗日方程推导出航天器的耦合动力学模型.姿态控制器设计过程中,首先构造固定时间...     

某航天器压紧释放装置结构设计与分析

为了给某微小型航天器设计一种新型的非火工压紧释放装置,采用了弹簧连杆式分离机构,对其可行性进行了分析。介绍了该压紧释放装置的工作原理,并通过理论计算求出该装置燃断器的燃断时间,然后进行试验验证,基于 ANSYS Workbench 软件进行了压紧状态下的随机振动仿真分析。结果表明,该燃断器的燃断时间可靠,理论值与试验值误差在15％以内,如果添加10 N 预拉力,燃断时间可减少约10％。在压紧状态下该装置振动环境适应性好,并且能够及时释放转子。     

DDS体系在飞行器地面测试系统中的应用

针对飞行器地面测试系统需要满足多种不同类型的数据传输、较高的数据传输速率、较高的数据传输实时性的目的,采用广播式网络通信体系DDS数据通信体系进行飞行器地面测试系统构建的方法。通过某型号飞行器地面测试以及各项大型试验。得出DDS数据通信体系具有高实时性、系统网络架构易于扩展、能够适应不同类型数据传输、数据通信模式灵活可配置等诸多结论,DDS数据通信体系完全能够满足飞行器地面测试的应用需求。     

神舟4号多模态微波遥感器散射计分系统

介绍神舟4号多模态微波遥感器散射计分系统的研制情况和在轨实验情况。首先简单介绍了系统组成、工作特点以及机载校飞实验, 随后介绍了数据处理过程以及遥感器地面信号处理系统的研制开发工作, 给出了在轨海面风场测量的实验结果以及亚马逊热带雨林的后向散射系数测量结果。     

载人航天中的防火安全与微重力燃烧研究

简要阐述了载人航天器防火安全的重要性、面临的问题及解决途径。介绍了防火安全措施。对载人航天任务中所涉及的微重力燃烧研究的领域、特点及途径予以讨论。     

大型空间飞行器的高阶滑模姿态控制律设计

针对大型空间飞行器的大角度姿态控制问题,考虑航天器惯量矩阵中的不确定性和外部扰动力矩,应用高阶滑模控制方法设计了姿态跟踪控制律.采用的二阶滑模控制方法改善了系统针对不确定性及外部扰动的鲁棒性,并减弱了振颤现象.针对所设计的控制器进行了仿真验证,并与一阶滑模控制进行了对比,仿真结果表明了所提出方法的有效性.     

Robust and optimal attitude control of spacecraft with disturbances

In this paper, a robust and optimal attitude control design that uses the Euler angles and angular velocities feedback is presented for regulation of spacecraft with disturbances. In the control design, it is assumed that the disturbance signal has the information of the system state. In addition, it is assumed that the disturbance signal tries to maximise the same performance index that the control input tries to minimise. After proposing a robust attitude control law that can stabilise the complete attitude motion of spacecraft with disturbances, the optimal attitude control problem of spacecraft is formulated as the optimal game-theoretic problem. Then it is shown that the proposed robust attitude control law is the optimal solution of the optimal game-theoretic problem. The stability of the closed-loop system for the proposed robust and optimal control law is proven by the LaSalle invariance principle. The theoretical results presented in this paper are illustrated by a numerical example.     

Manoeuvring and vibration reduction of a flexible spacecraft integrating optimal sliding mode controller and distributed piezoelectric sensors/actuators

This investigation is to apply optimal sliding mode (OSM) control theory and distributed piezoelectric sensor/actuator technology to vibration control of a flexible spacecraft. An approximate analytical dynamic model of a slewing flexible spacecraft with surface‐bonded piezoelectric sensors/actuators is developed using Hamilton's principle with discretization by assumed model method. To satisfy pointing requirements and simultaneously suppress vibration, two separate control loops are adopted. The first uses the piezoceramics as sensors and actuators to actively suppress certain flexible modes by designing a positive position feedback (PPF) compensators that add damping to the flexible structures in certain critical modes in the inner feedback loop; then a second feedback loop is designed using OSM control to slew the spacecraft. The OSM controller minimizes the expected value of a quadratic objective function consisting of only the states with the constraints that the error states always remain on the intersection of sliding surfaces. The advantage in this method is that the vibration reduction and attitude control are achieved separately in the two separate feedback loops, allowing the pointing requirements and simultaneous vibrations suppression to be satisfied independently of one another. An additional attraction of the design method is that the selection of PPF gain is determined by introducing a cost function to be minimized by the feedback gains which are subject to the stability criterion at the same time, such that the feedback gains are selected in a more systematical way to avoid the arbitrary selecting of feedback gains. The proposed control strategy has been implemented on a flexible spacecraft, which is a hub with a cantilever flexible beam appendage and can undergo a single axis rotation. Both analytical and numerical results are presented to show the theoretical and practical merits of this approach. Copyright © 2006 John Wiley & Sons, Ltd.     

MEMS陀螺在航天器控制系统中的应用评述

在分析MEMS陀螺在空间应用优势基础上,对MEMS陀螺的空间适应性进行了分析,提出了其在空间系统中的应用途径,通过国内外应用情况表明:MEMS陀螺能够广泛应用于航天器控制系统,并随着工艺水平的提高,将成为航天器控制系统的最佳选择.     

基于数据驱动的航天器产品热处理技术

航天器研制任务呈现快速增长态势,趋向于批量化、快速响应、柔性定制等特性,但传统航天器热处理过程以手工操作为主,人工巡查记录数据,存在生产装备数字化差,过程数据及时性、准确性、完整性差,缺乏大数据分析的问题。以基于数据驱动的模块化工艺技术研究为核心,开展模块化工艺设计与执行;以热处理生产装备数字化及自主健康管理技术研究为基础,开展数字化装备与工艺技术等研究;以生产数据自动采集与集成、大数据分析技术研究为手段,开展数据自动采集与集成、质量问题分析与决策等研究,实现热处理生产装备数字化,热处理生产过程数字化管控,热处理过程数据自动采集与大数据分析,实现特种工艺信息化,显著提升宇航产品热处理本质生产能力。