卡尔曼滤波技术在自旋卫星姿态确定中的研究与应用

卫星执行飞行任务时,对卫星的定向都有预定的要求。星上控制系统与地面测控系统都需要姿态确定的信息,因此如何利用卫星遥测数据来确定卫星姿态非常必要。通过引入一个离散控制过程的系统,推导出应用于自旋卫星姿态确定的卡尔曼滤波过程。根据量测量的获取情况,首先对量测量全部正常获取时的卡尔曼滤波定姿计算方法和步骤进行详细论述,然后对其他情况下的滤波进行描述,最后给出应用情况分析。     

自旋卫星红外地中脉冲丢失情况下姿态确定分析与应用

实际应用中,由于遥测故障或脉冲重叠等多种原因,获取姿态脉冲信息时,可能缺少某些测量脉冲,为姿态确定的方法选择造成一定难度。针对海上测量弧段,某自旋卫星在红外地中脉冲丢失,仅有地出脉冲以及太1、太2脉冲时的几何定姿方法问题,通过对其原理、概念进行分析,制定自旋卫星红外地中脉冲丢失情况下定姿的方案与方法。该方法主要用于海上实时姿态监视,应急情况下也可以用于姿态的粗控。该研究为航天测量船应用测控软件的设计提供了良好基础。     

细长型双自旋静止卫星测控仿真

本文介绍了在计算机上进行细长型双自旋卫星姿态、轨道和重要遥测参数仿真的原理和方案。该方案考虑了卫星章动运动对姿态的影响，根据实时性和精度的要求，模拟卫星实际测控过程，对各种遥测量进行了仿真。基于该方案的仿真程序通过了星地大回路演练的检验，达到了预期的要求和目的。     

基于导航接收机的自旋卫星姿态确定方法

提出了一种基于单天线导航接收机跟踪环路载波相位差的自旋卫星姿态确定方法。以导航接收机锁相环鉴别器输出的载波相位差为数据源,推导了从载波相位变化中获得卫星姿态信息的算法模型。在天线安装半径0.3m,自旋速率20r/min,载波相位测量误差3mm,角速率测量误差0.1(°)/s条件下进行仿真,获得自旋卫星主轴在空间惯性坐标系中的定向精度为2.17°。研究表明用单天线导航接收机确定对低转速、低精度角速率陀螺自旋卫星姿态是可行的,与传统多天线接收机载波相位差测量方法相比,有体积小、低能耗和避免整周模糊度计算等优点。     

一种确定自旋卫星姿态的新方法

提出了一种在自旋稳定卫星自旋轴与几何体轴重合或几乎重合时只利用太阳角计算自旋卫星姿态的方法。给出了方法的原理及适用范围。研究表明：定姿精度仅与太敏测量精度有关,减小了传统方法中太敏与地敏两项测量误差产生的误差,方法原理简单、精度高。由实际卫星数据的长期验证可知：方法能在卫星自旋轴与实际几何轴偏差较小时实现快速定姿,定姿结果满足要求。     

用箭遥数据计算三轴稳定卫星初始姿态

在卫星发射中,利用星箭分离时刻的火箭遥测数据来确定卫星在入轨时的初始姿态,是主动段测控任务中准实时工作很重要的一环。文中从初始姿态确定的原理入手,对数据的选取和坐标系的定义进行描述,并对计算方法和步骤进行了讨论。通过实际应用,指出应注意的事项。     

实践四号卫星姿态测量系统与数据处理

采用太阳敏感器和磁强计构成卫星姿态测量系统实践四号卫星自旋轴相对太阳矢量,地磁矢量的方位以确定卫星相对于惯性空间的方位和卫星自旋转速,以及卫星章动信息,并给出了数据处理算法和结果。     

双自旋卫星的姿态运动和控制

本文引入卫星动力学等效概念,把单自旋卫星的动力学分析、制控的概念和方法推广应用到双自旋卫星。提出了双自旋卫星的双脉冲闭路控制的设计方案。分析了由于结构误差引起的摆动,给出了摆动角的计算公式和卫星姿态的稳定判据。论证了管一球武章动阻尼器也适用于双自旋卫星。证明了章动阻尼器不能消除摆动,甚至对卫星姿态误差产生不可忽视的影响;最大姿态误差角等于章动角和摆动角之和。最后,用仿真试验验证了分析结果。     

地球同步自旋稳定卫星的姿态确定方法及其微机实现

本文系作者根据航天部中国空间技术研究院和意大利国家研究委员会联合研究“卫星飞行动力学系统”课题的协议与意大利有关专家共同在微机上完成的自旋稳定地球同步卫星姿态确定的研究工作。文中提出了适用于不同轨道几何条件的六种确定性姿态确定模型。首先用批量最小二乘法统计确定卫星姿态,估计出系统误差,然后从实际量测中消去所估计出的系统误差,最后用修正过的数据按确定性姿态确定方法定出卫星姿态。文中给出了姿态确定方法的微机实现程序。仿真结果证明,本方法与大型机IBM 3081上取得的结果完全相同。     

自旋卫星姿态确定自适应卡尔曼滤波

本文根据自适应原理和仿真计算,对自旋卫星转移轨道的卡尔曼滤波姿态确定进行了分析,得到了一个简单可行的自适应方案,在较大的安装误差和章动角情况下,利用不太复杂的滤波模型和1000组左右量测数据,就能获得较高的姿态确定精度。     

Uncontrolled Attitude Motion of the Foton-12 Satellite and Quasi-Steady Microaccelerations onboard It

The results of determination of the uncontrolled attitude motion of the Foton-12 satellite (placed in orbit on September 9, 1999, terminated its flight on September 24, 1999) are presented. The determination was carried out by the onboard measurement data of the Earth's magnetic field strength vector. Intervals with a duration of several hours were selected from data covering almost the entire flight. On each such interval the data were processed simultaneously using the least squares method by integrating the satellite's equations of motion with respect to the center of mass. The initial conditions of motion and the parameters of the mathematical model employed were estimated in processing. The results obtained provided for a complete representation of the satellite's motion during the flight. This motion, beginning with a small angular velocity, gradually sped up. The growth of the component of the angular velocity with respect to the longitudinal axis of the satellite was particularly strong. During the first several days of the flight this component increased virtually after every passage through the orbit's perigee. As the satellite's angular velocity increased, its motion became more and more similar to the regular Euler precession of an axisymmetric rigid body. In the last several days of flight the satellite's angular velocity with respect to its longitudinal axis was about 1 deg/s and the projection of the angular velocity onto the plane perpendicular to this axis had a magnitude of approximately 0.15 deg/s. The deviation of the longitudinal axis from the normal to the orbit plane did not exceed 60°. The knowledge of the attitude motion of the satellite allowed us to determine the quasi-steady microacceleration component onboard it at the locations of the technological and scientific equipment.     

在轨地球同步卫星地球敏感器干扰及指向计算

从工程应用角度,基于太阳、月球位置和卫星轨道根数推导了太阳和月球对地球同步轨道卫星红外地球敏感器干扰的计算公式及预报方法,同时给出了安全模式下卫星Z轴跟踪太阳时星上天线指向变化的计算模型。计算结果和卫星下传遥测数据验证了方法的正确性,可用于实际卫星管理。     

星载合成孔径雷达的运动效应

对星载合成孔径雷达的运动效应进行了详细的分析，给出了雷达回波的多普勒参数和距离徒动特性的一般关系式。详细论证了卫星运动对多普勒参数和成像的影响，导出了描述速度误差、加速度误差和姿态误差的一系列定量计算公式，并就运动误差的补偿方法进行了阐述。     

太阳,地球,卫星相关模拟源设计

“风云二号”自旋稳定地球同步气象卫星，以地球脉冲作为姿态控制基准，以太阳脉冲作为图像扫描基准，太阳、地球、卫星三者之间的相对关系在连续不断地运动变化。为了验证扫描成像原理和在地面测试卫星的成像质量，需对三者的相对关系进行研究。在此基础上，研制出太阳、地球、卫星相关模拟源，成功地用电子信号准确模拟“风云二号”卫星在静止轨道上感受到的不断变化的太阳、地球信号，使卫星的成像测试顺利进行，同时发现了卫星设计中存在的问题。     

Low-Frequency Microaccelerations onboard the Foton-11 Satellite

We analyze the microacceleration measurements carried out onboard the Foton-11 satellite with the three-component accelerometer BETA. The microaccelerations were recorded virtually throughout the entire orbital flight of the Foton-11 satellite. The data obtained were analyzed in the following way. First they were used to determine the actual rotational motion of the satellite for several arbitrarily selected time intervals 4 h long. This problem was solved by constructing the approximation of the microacceleretation low-frequency component (previously determined from the data) by its calculated analog computed along the solutions to differential equations of rotational motion of the satellite. The approximation was made by the least squares method. As a result, those mathematical model parameters and the solutions to equations of motion were found that gave the best consistency of the microacceleretation low-frequency component and its calculated analog. Then the spectral analysis of the low-frequency component and its calculated analog was made. It was shown that, although basic harmonics of these functions coincided sufficiently well, some harmonics of the low-frequency component failed to be interpreted in terms of the satellite's rotational motion.     

某遥感卫星热分析技术研究

基于卫星热试验与热分析状态差异性分析,根据某遥感卫星热分析和热平衡试验结果,用综合虚拟热试验和有限元的有限差分集成法对其热模型修正技术进行了研究。卫星在轨温度遥测结果表明热模型修正有效。     

星相数据的姿态确定

本文给出了利用卫星拍摄的星相数据计算卫星姿态的数学关系式和计算方法。经实际使用证明这种方法是正确的。     

An Analysis of the Low-Frequency Component in Measurements of Angular Velocity and Microacceleration onboard the Foton-12 Satellite

We compare the results of two methods used to determine the angular velocity of the Foton-12 satellite and the low-frequency component of microaccelerations onboard it. The first method is based on reconstruction of the satellite's rotational motion using the data of onboard measurements of the strength of the Earth's magnetic field. The motion (time dependence of the orientation parameters and angular velocity) was found from the condition of best approximation of the measurement data by the functions calculated along the solutions to equations of attitude motion of the satellite. The solutions found were used to calculate the quasistatic component of microaccelerations at certain points of the satellite, in particular, at the point of location of an accelerometer of the QSAM system. Filtration of the low-frequency component of the angular velocity and microacceleration from the data of measurements by a sensor of angular velocity and by the accelerometer of this system served as a second method. The filtration was made using the discrete Fourier series. A spectral analysis of the functions representing the results of determining the angular velocity and microacceleration by both methods is performed. Comparing the frequencies and amplitudes of the harmonic component of these functions allowed us to estimate the accuracy of measurements made by the QSAM system in the low-frequency range.