公开(公告)号：US06330988B1

公开(公告)日：2001-12-18

申请号：US09628779

申请日：2000-07-29

申请人： Yong Liu ,  Yeong-Wei Andy Wu ,  Rongsheng Li

发明人： Yong Liu ,  Yeong-Wei Andy Wu ,  Rongsheng Li

IPC分类号： B64G124

CPC分类号： B64G1/361

摘要： An apparatus for star catalog equalization to enhance attitude determination includes a star tracker, a star catalog and a controller. The star tracker is used to sense the positions of stars and generate signals corresponding to the positions of the stars as seen in its field of view. The star catalog contains star location data that is stored using a primary and multiple secondary arrays sorted by both declination (DEC) and right ascension (RA), respectively. The star location data stored in the star catalog is predetermined by calculating a plurality of desired star locations, associating one of a plurality of stars with each of the plurality of desired star locations based upon a neighborhood association angle to generate an associated plurality of star locations: If an artificial star gap occurs during association, then the neighborhood association angle for reassociation is increased. The controller uses the star catalog to determine which stars to select to provide star measurement residuals for correcting gyroscope bias and spacecraft attitude.

摘要翻译： 用于星型目录均衡以增强姿态确定的装置包括星形跟踪器，星形目录和控制器。 星形跟踪器用于感测恒星的位置，并产生与其视场中所见的恒星位置相对应的信号。 星型目录包含使用分别由偏角（DEC）和右升高（RA）排序的主要和多个辅助阵列存储的星形位置数据。 存储在星形目录中的星形位置数据是通过计算多个所需的星形位置来预先确定的，所述星形位置基于邻域关联角将多个恒星中的一个与多个所需星形位置中的每一个相关联，以产生相关联的多个星形位置 ：如果在关联期间发生人造星差距，则重新关联的邻域关联角度增加。 控制器使用星形目录来确定选择哪颗星以提供星测量残差来校正陀螺仪偏差和航天器姿态。

公开(公告)号：US06304822B1

公开(公告)日：2001-10-16

申请号：US09629961

申请日：2000-08-01

申请人： Yong Liu ,  Yeong-Wei Andy Wu ,  Rongsheng Li

发明人： Yong Liu ,  Yeong-Wei Andy Wu ,  Rongsheng Li

IPC分类号： G01C2100

CPC分类号： B64G1/361 ,  B64G2001/245 ,  G01C21/24 ,  G01S3/7867 ,  G05D1/0883

摘要： Methods are provided for dynamically processing successively-generated star tracker data frames and associated valid flags to generate processed star tracker signals that have reduced noise and a probability greater than a selected probability Pslctd of being valid. These methods maintain accurate spacecraft attitude control in the presence of spurious inputs (e.g., impinging protons) that corrupt collected charges in spacecraft star trackers. The methods of the invention enhance the probability of generating valid star tracker signals because they respond to a current frame probability Pfrm by dynamically selecting the largest valid frame combination whose combination probability Pcmb satisfies a selected probability Pslctd. Noise is thus reduced while the probability of finding a valid frame combination is enhanced. Spacecraft structures are also provided for practicing the methods of the invention.

摘要翻译： 提供了用于动态处理连续产生的星形跟踪器数据帧和相关联的有效标志的方法，以产生具有减小的噪声的处理的星形跟踪器信号和大于所选择的有效概率Pslctd的概率。 这些方法在存在损坏航天器星形跟踪器收集的费用的杂散输入（例如撞击质子）的情况下，保持准确的航天器姿态控制。 本发明的方法通过动态地选择组合概率Pcmb满足选定概率Pslctd的最大有效帧组合来响应当前帧概率Pfrm，增强了产生有效星迹跟踪信号的概率。 因此降低了噪声，同时增强了找到有效帧组合的概率。 还提供了航天器结构来实施本发明的方法。

公开(公告)号：US06288671B1

公开(公告)日：2001-09-11

申请号：US09557378

申请日：2000-04-25

申请人： Yeong-Wei Andy Wu ,  Umesh S. Ketkar ,  Rongsheng Li ,  Richard Y. Chiang

发明人： Yeong-Wei Andy Wu ,  Umesh S. Ketkar ,  Rongsheng Li ,  Richard Y. Chiang

IPC分类号： H04B7185

CPC分类号： G01S3/30 ,  G01S5/0247 ,  G01S19/38

摘要： Control systems and methods are provided which enhance acquisition range, transient response and offset pointing accuracy in beacon-assisted orientation of a spacecraft to a desired spacecraft attitude Adsrd. The methods receive a beacon signal with antennas that are arranged in a fixed angular relationship to thereby form an attitude error signal Serr whose magnitude is a measure of the attitude difference between a current spacecraft attitude Acrnt and the desired spacecraft attitude Adsrd. A sum power P&Sgr; that is the sum of the signal powers from the antennas is sensed and a signal modifier Smod is generated that increases with decreases in the sum power P&Sgr;. The attitude error signal Serr is then modified with a term (1+Smod) to form an enhanced attitude error signal Serrenhd. In one embodiment, the signal modifier Smod is n|Pmax−P&Sgr;|m wherein n and m are positive numbers and Pmax is the sum power P&Sgr; when the attitude error is zero.

摘要翻译： 提供了控制系统和方法，其增强了航天器信标辅助定向到期望的航天器姿态的采集范围，瞬态响应和偏移指向精度Adsrd。 该方法接收具有以固定角度关系布置的天线的信标信号，从而形成姿态误差信号Serr，其大小是当前航天器姿态Acrnt与期望的航天器姿态Adsrd之间的姿态差的度量。 检测作为来自天线的信号功率的总和的总功率PSIGMA，并且产生信号修正器Smod，其随和功率PSIGMA的减小而增加。 然后用项（1 + Smod）修改姿态误差信号Serr，以形成增强的姿态误差信号Serrenhd。 在一个实施例中，信号修正器Smod是n | Pmax-PSIGMA | m，其中n和m是正数，Pmax是姿态误差为零时的和功率PSIGMA。

公开(公告)号：US06317662B1

公开(公告)日：2001-11-13

申请号：US09624270

申请日：2000-07-24

申请人： Rongsheng Li ,  Yeong-Wei Andy Wu

发明人： Rongsheng Li ,  Yeong-Wei Andy Wu

IPC分类号： G06F1700

CPC分类号： G05B13/04

摘要： The stability of a recursive estimator process (e.g., a Kalman filter is assured for long time periods by periodically resetting an error covariance P(tn) of the system to a predetermined reset value Pr. The recursive process is thus repetitively forced to start from a selected covariance and continue for a time period that is short compared to the system's total operational time period. The time period in which the process must maintain its numerical stability is significantly reduced as is the demand on the system's numerical stability. The process stability for an extended operational time period To is verified by performing the resetting step at the end of at least one reset time period Tr whose duration is less than the operational time period To and then confirming stability of the process over the reset time period Tr. Because the recursive process starts from a selected covariance at the beginning of each reset time period Tr, confirming stability of the process over at least one reset time period substantially confirms stability over the longer operational time period To.

摘要翻译： 递归估计器过程的稳定性（例如，卡尔曼滤波器通过周期性地将系统的误差协方差P（tn）重置为预定的复位值Pr来确保长时间周期。因此递归过程被重复地从一个 选择的协方差，并持续一段与系统总运行时间相比较短的时间段，过程必须保持其数值稳定性的时间段显着减少，对系统的数值稳定性的要求， 延长的工作时间段To通过在至少一个持续时间小于操作时间段的至少一个复位时间段Tr的结束执行复位步骤来验证，然后确认过程在复位时间段Tr上的稳定性由于递归 过程从每个复位时间段Tr的开始处的选择的协方差开始，确认过程至少在o上的稳定性 复位时间段在较长的操作时间段To基本上确认了稳定性。

公开(公告)号：US06691033B1

公开(公告)日：2004-02-10

申请号：US09625392

申请日：2000-07-26

申请人： Rongsheng Li ,  Yeong-Wei Andy Wu ,  Douglas H. Hein

发明人： Rongsheng Li ,  Yeong-Wei Andy Wu ,  Douglas H. Hein

IPC分类号： G01C2100

CPC分类号： B64G1/361 ,  G01C21/025

摘要： A method and apparatus for determining star tracker misalignments is disclosed. The method comprises the steps of defining a defining a reference frame for the star tracker assembly according to a boresight of the primary star tracker and a boresight of a second star tracker wherein the boresight of the primary star tracker and a plane spanned by the boresight of the primary star tracker and the boresight of the second star tracker at least partially define a datum for the reference frame for the star tracker assembly; and determining the misalignment of the at least one star tracker as a rotation of the defined reference frame.

摘要翻译： 公开了一种用于确定星形跟踪器未对准的方法和装置。 该方法包括以下步骤：根据主星形跟踪器的视点和第二星形跟踪器的视轴定义用于星形跟踪器组件的参考框架，其中主星形跟踪器的视轴和由主轴的视轴跨越的平面 主星形跟踪器和第二星形跟踪器的视轴至少部分地定义用于星形跟踪器组件的参考系的基准; 以及确定所述至少一个星形跟踪器的未对准作为所述限定的参考帧的旋转。

公开(公告)号：US06285927B1

公开(公告)日：2001-09-04

申请号：US09318565

申请日：1999-05-26

申请人： Rongsheng Li ,  Yeong-Wei Andy Wu

发明人： Rongsheng Li ,  Yeong-Wei Andy Wu

IPC分类号： B64G124

CPC分类号： G05D1/0883 ,  B64G1/24 ,  B64G1/288 ,  B64G1/36 ,  B64G1/361 ,  B64G1/363 ,  B64G1/365 ,  B64G2001/245 ,  G01C21/025

摘要： A method and system for minimizing attitude errors resulting from dynamic spacecraft maneuvers or time-varying mismatched attitude sensor measurements. The method includes time-tagging a primary attitude value from a primary attitude sensor and storing the value and associated time stamp in a buffer. A secondary attitude value, generated by a secondary attitude sensor, having a different associated time-stamp is then time-matched to the primary attitude valve. The corrected spacecraft attitude is then calculated as a function of the time-matched primary and secondary attitude values. In one aspect of the invention, the primary attitude sensor generates attitude data at a faster rate than the secondary attitude sensor. This primary attitude data is stored in a buffer such that, when the secondary attitude data becomes available, several nearest-in-time primary attitude data points are retrieved from the buffer. These data points are then used to interpolate a higher time-matched resolution data point. This, in turn, is used along with the secondary attitude data point in updating the spacecraft attitude.

摘要翻译： 一种用于最小化由动态航天器操纵或时变不对称姿态传感器测量引起的姿态误差的方法和系统。 该方法包括从主姿态传感器对主要姿态值进行时间标记，并将该值和相关联的时间戳存储在缓冲器中。 然后，由二次姿态传感器产生的具有不同相关联的时间戳的二次姿态值与主姿势阀进行时间匹配。 然后根据时间匹配的主要和次要姿态值来计算校正的航天器姿态。 在本发明的一个方面，主姿态传感器以比二次姿态传感器更快的速度生成姿态数据。 该主要态度数据被存储在缓冲器中，使得当二级姿态数据变得可用时，从缓冲器检索几个最接近时间的主姿势数据点。 然后将这些数据点用于内插较高时间匹配的分辨率数据点。 这反过来又与二级姿态数据点一起用于更新航天器的态度。

公开(公告)号：US06362464B1

公开(公告)日：2002-03-26

申请号：US09504543

申请日：2000-02-15

申请人： Yong Liu ,  Yeong-Wei A. Wu ,  Rongsheng Li ,  Christopher L. Rice

发明人： Yong Liu ,  Yeong-Wei A. Wu ,  Rongsheng Li ,  Christopher L. Rice

IPC分类号： G01C2102

CPC分类号： B64G1/361 ,  G01C21/025 ,  G01S3/7867 ,  G05D1/0883

摘要： An apparatus for determining stellar inertial attitude based upon a plurality of stars includes a star tracker and a controller. The star tracker is used to sense the positions of stars and generate signals corresponding to the positions of the stars as seen in its field of view. The controller checks a star catalog and actively determines which stars to track. The controller does this determination in terms of each star's relative geometry. The controller then commands the star tracker to track these stars and uses them to determine the spacecraft attitude.

摘要翻译： 一种用于根据多个恒星确定恒星惯性姿态的装置包括星形跟踪器和控制器。 星形跟踪器用于感测恒星的位置，并产生与其视场中所见的恒星位置相对应的信号。 控制器检查星号目录，并主动确定要跟踪的星星。 控制器根据每颗星的相对几何来做出这一决定。 然后，控制器命令星形跟踪器跟踪这些恒星并使用它们来确定航天器的姿态。

公开(公告)号：US06356815B1

公开(公告)日：2002-03-12

申请号：US09648501

申请日：2000-08-25

申请人： Yeong-Wei A. Wu ,  Rongsheng Li ,  Yong Liu

发明人： Yeong-Wei A. Wu ,  Rongsheng Li ,  Yong Liu

IPC分类号： G01C2102

CPC分类号： B64G1/361 ,  G01C21/025 ,  G01S3/7867 ,  G01S5/163 ,  G05D1/0883

摘要： Stellar attitude-control systems and methods are provided with enhanced accuracy because they recognize that important star tracker errors exhibit a boresight symmetry and that these errors can be accurately defined by weighting a measurement-noise covariance matrix R(tn) with variances that are functions of off-boresight angles of detected stars. A method of the invention derives off-boresight angles &thgr; from star-tracker signals of detected stars. These off-boresight angles &thgr; are combined with variance coefficients &agr; to generate off-boresight variances rob(tn) that are functions of the off-boresight angles &thgr; and, in particular, correspond to star tracker color shift errors. A gain matrix K(tn) is then calculated with a weighted measurement-noise covariance matrix R(tn) that includes the off-boresight variances rob(tn). This gain matrix is used to generate an attitude estimate matrix X*(tn) for use in spacecraft attitude control. The variance coefficients &agr; are preferably modified to include star tracker focal length shift errors which are also a function of off-boresight angles &thgr;. It is noted that the variance coefficients &agr; can be reduced by identifying the spectral classes of detected and identified stars. The invention recognizes that Other star tracker errors that are not functions of off-boresight angles are modeled with appropriate constant variances rc(tn) that are used to modify the covariance matrix R(tn).

摘要翻译： 提供恒星姿态控制系统和方法具有更高的精度，因为它们认识到重要的星形跟踪器误差表现出视轴对称性，并且可以通过对作为功能的方差加权测量噪声协方差矩阵R（t​​n）来精确地定义这些误差。 检测到的星的偏离视角。 本发明的一种方法从检测到的恒星的星形跟踪信号中导出离视角θ。 这些离开视轴角度θ与方差系数α组合以产生作为离开视角θ的函数的离开视轴方向rob（tn），特别是对应于星形跟踪器颜色偏移误差。 然后使用包括偏离视差方差rob（tn）的加权测量 - 噪声协方差矩阵R（t​​n）来计算增益矩阵K（tn）。 该增益矩阵用于生成用于航天器姿态控制的姿态估计矩阵X *（tn）。 方差系数α优选地被修改为包括也是偏离视角θ的函数的星形跟踪器焦距偏移误差。 应注意，可以通过识别检测到和识别的星的光谱类别来减小方差系数α。 本发明认识到，不是非视距角函数的其他星形跟踪器误差是用用于修改协方差矩阵R（t​​n）的适当常数变量rc（tn）进行建模的。

公开(公告)号：US20080046138A1

公开(公告)日：2008-02-21

申请号：US11221646

申请日：2005-09-07

申请人： Richard Fowell ,  Rongsheng Li ,  Yeong-Wei Wu

发明人： Richard Fowell ,  Rongsheng Li ,  Yeong-Wei Wu

IPC分类号： B64G1/36

CPC分类号： B64G1/36 ,  G05D1/0883

摘要： A method for controlling an actuator of a vehicle comprises providing a dynamic condition sensor generating a vehicle movement signal and a position sensor for generating a reported position. A processor is coupled to the inertial sensor and the position sensor and comprises an estimator, a position measurement predictor having a filter, a comparator and a control shaping block, said estimator generating a vehicle position based upon the dynamic condition sensor, said position measurement predictor generating an estimated position measurement in response to the reported vehicle position and a matched frequency response to the movement signal, said control shaping block generating an actuator control signal in response to a comparison of the estimated position measurement and the reported vehicle position.

摘要翻译： 一种用于控制车辆的致动器的方法包括提供产生车辆运动信号的动态条件传感器和用于产生报告位置的位置传感器。 处理器耦合到惯性传感器和位置传感器，并且包括估计器，具有滤波器的位置测量预测器，比较器和控制整形块，所述估计器基于动态条件传感器产生车辆位置，所述位置测量预测器 响应于所报告的车辆位置和对所述移动信号的匹配的频率响应来产生估计位置测量，所述控制整形块响应于所估计的位置测量和报告的车辆位置的比较而产生致动器控制信号。

公开(公告)号：US07219014B2

公开(公告)日：2007-05-15

申请号：US10709346

申请日：2004-04-29

申请人： David D. Needelman ,  Rongsheng Li ,  Richard A. Fowell ,  Peter C. Lai ,  Yeong-Wei A. Wu ,  Bruce N. Eyerly ,  Jonathan French

发明人： David D. Needelman ,  Rongsheng Li ,  Richard A. Fowell ,  Peter C. Lai ,  Yeong-Wei A. Wu ,  Bruce N. Eyerly ,  Jonathan French

IPC分类号： G01C21/00 ,  G05D1/00

CPC分类号： B64G1/361 ,  G01C22/00

摘要： A vehicle (12) including a control system (18) is used for controlling vehicle attitude or angular velocity (38). The processor (24) is coupled to a star sensor or tracker (22) and a memory (30) that may include a star catalog (32), and an exclusion list (36). The exclusion list (36), a list of stars to be temporarily excluded from consideration when determining attitude or angular velocity or relative alignment of star sensors or trackers, is calculated on-board. Such a calculation prevents the necessity for a costly, periodic, ground calculation and upload of such data. By manipulating the star catalog, or sub-catalogs derived from said catalog, based upon the exclusion list (36), measurements of such excluded stars are prevented from corrupting the attitude or angular velocity or alignment estimates formulated on board.

摘要翻译： 包括控制系统（18）的车辆（12）用于控制车辆姿态或角速度（38）。 处理器（24）耦合到星形传感器或跟踪器（22）和可包括星形目录（32）的存储器（30）和排除列表（36）。 排除列表（36），在确定姿态或角速度或星形传感器或跟踪器的相对对齐时暂时排除考虑的恒星列表。 这样的计算可以防止对这些数据进行昂贵，周期性，地面计算和上传的必要性。 通过根据排除列表（36）操纵从所述目录导出的星号目录或子目录，防止这些排除的星星的测量破坏了在船上制定的姿态或角速度或对准估计。