Patents by Inventor Rongsheng Li

Rongsheng Li has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20050108884
    Abstract: A method of calibrating a gyro (42) of a spacecraft (14) may include determining a yaw attitude residual of the spacecraft. Roll gyro bias residual is determined in response to the yaw attitude residual. The gyro (42) is calibrated in response to the roll gyro bias residual. A method of calibrating a gyro (42) of a spacecraft (14) may alternatively include disabling gyro calibration, gain scheduling, or resetting attitude and gyro bias covariance, for selective axes, for a yaw transient period. The gyro (42) is calibrated in a nominal fashion after completion of the yaw transient period.
    Type: Application
    Filed: November 26, 2003
    Publication date: May 26, 2005
    Inventors: Hangching Wang, Rongsheng Li
  • Publication number: 20050071055
    Abstract: A method and apparatus for refining a spacecraft state estimate, such as an attitude estimate or an angular velocity estimate, is disclosed. The method computes a plurality equations using residuals describing the difference between observed star positions and predicted positions based on inertial measurements, and solves those equations to generate refined estimates of the spacecraft state estimates.
    Type: Application
    Filed: September 21, 2004
    Publication date: March 31, 2005
    Inventors: David Needelman, Rongsheng Li, Yeong-Wei Wu
  • Patent number: 6863244
    Abstract: A method, apparatus, article of manufacture, and a memory structure for compensating for optical sensor data corrupted by angular acceleration is disclosed. The method comprises the steps of determining an angular acceleration of the optical sensor and modifying the optical sensor data according to the determined angular acceleration of the optical sensor. The apparatus comprises a sensor for determining an angular acceleration of the optical sensor and a navigation system for modifying the optical sensor data according to the determined angular acceleration of the optical sensor.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: March 8, 2005
    Assignee: The Boeing Company
    Inventors: Richard A. Fowell, Salma I. Saeed, Rongsheng Li, Yeong-Wei Wu
  • Publication number: 20050049764
    Abstract: A method and apparatus for estimating spacecraft momentum is disclosed. The method comprises the steps of generating a plurality of spacecraft momentum measurements, fitting the plurality of spacecraft momentum measurements to a parametric model of a spacecraft momentum profile having a time period of tp, determining the momentum of the spacecraft from the parametric model; and generating an estimate of the momentum to be removed from the spacecraft at least in part from the determined momentum of the spacecraft.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 3, 2005
    Inventors: Hanching Wang, Rongsheng Li
  • Publication number: 20050010337
    Abstract: A method and apparatus for estimating a slave payload attitude is disclosed. The method comprises the steps of accepting a plurality of slave payload attitude measurements, deriving a model of the relative attitude of the slave payload and a master payload attitude at least in part from the plurality of slave attitude measurements, predicting the relative attitude between the slave payload attitude and the master payload attitude using the derived model, and estimating the relative attitude between the slave payload attitude and the master payload attitude at least in part from the predicted relative attitude between the slave payload attitude and the master payload attitude. Furthermore, the absolute attitude of the slave payload is computed using the relative attitude and the master payload attitude.
    Type: Application
    Filed: June 25, 2004
    Publication date: January 13, 2005
    Inventors: Rongsheng Li, Hanching Wang, Yeong-Wei Wu
  • Patent number: 6825806
    Abstract: Methods and structures are provided for reducing pointing errors &zgr; of satellite antennas and for generating broad field-of-view satellite attitude acquisition patterns. In one method embodiment, satellite transmit beams have estimated pointing attitudes &bgr; and are transmitted to overlap on a ground-based receiving terminal which has a known terminal location &lgr; and which measures received signal strengths &agr;. Pointing errors &zgr; of the transmit beams are then determined from the estimated pointing attitudes &bgr;, the terminal location &lgr; and the signal strengths &agr; and the pointing errors &zgr; are subsequently reduced by revising the pointing attitudes &bgr;. Other method embodiments utilize known signal-strength functions and antenna signals with known signal parameters such as frequencies and/or modulations.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: November 30, 2004
    Assignee: The Boeing Company
    Inventors: Ketao Liu, Richard Fowell, Yeong-Wei A. Wu, Rongsheng Li
  • Publication number: 20040148068
    Abstract: A method, apparatus, article of manufacture, and a memory structure for compensating for optical sensor data corrupted by angular acceleration is disclosed. The method comprises the steps of determining an angular acceleration of the optical sensor and modifying the optical sensor data according to the determined angular acceleration of the optical sensor. The apparatus comprises a sensor for determining an angular acceleration of the optical sensor and a navigation system for modifying the optical sensor data according to the determined angular acceleration of the optical sensor.
    Type: Application
    Filed: February 7, 2003
    Publication date: July 29, 2004
    Inventors: Richard A. Fowell, Salma I. Saeed, Rongsheng Li, Yeong-Wei Wu
  • Patent number: 6766227
    Abstract: Attitude acquisition methods and systems are provided which reduce the time generally required to acquire spacecraft attitude estimates and enhance the probability of realizing such estimates. The methods and systems receive, over a time span &Dgr;t, successive frames of star-sensor signals that correspond to successive stellar fields-of-view, estimate spacecraft rotation &Dgr;r throughout at least a portion of the time span &Dgr;t, and, in response to the spacecraft rotation &Dgr;r, process the star-sensor signals into a processed set of star-sensor signals that denote star positions across an expanded field-of-view that exceeds any of the successive fields-of-view. The expanded field-of-view facilitates identification of the stars that generated the processed set of star-sensor signals to thereby acquire an initial attitude estimate.
    Type: Grant
    Filed: November 19, 2002
    Date of Patent: July 20, 2004
    Assignee: The Boeing Company
    Inventors: David D. Needelman, Yeong-Wei A. Wu, Rongsheng Li
  • Publication number: 20040098177
    Abstract: Attitude acquisition methods and systems are provided which reduce the time generally required to acquire spacecraft attitude estimates and enhance the probability of realizing such estimates. The methods and systems receive, over a time span &Dgr;t, successive frames of star-sensor signals that correspond to successive stellar fields-of-view, estimate spacecraft rotation &Dgr;r throughout at least a portion of the time span &Dgr;t, and, in response to the spacecraft rotation &Dgr;r, process the star-sensor signals into a processed set of star-sensor signals that denote star positions across an expanded field-of-view that exceeds any of the successive fields-of-view. The expanded field-of-view facilitates identification of the stars that generated the processed set of star-sensor signals to thereby acquire an initial attitude estimate.
    Type: Application
    Filed: November 19, 2002
    Publication date: May 20, 2004
    Applicant: The Boeing Company
    Inventors: David D. Needelman, Yeong-Wei A. Wu, Rongsheng Li
  • Patent number: 6691033
    Abstract: 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.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: February 10, 2004
    Assignee: Hughes Electronics Corporation
    Inventors: Rongsheng Li, Yeong-Wei Andy Wu, Douglas H. Hein
  • Patent number: 6681159
    Abstract: Methods and structures are provided that enhance attitude control during gyroscope substitutions by insuring that a spacecraft's attitude control system does not drive its absolute-attitude sensors out of their capture ranges. In a method embodiment, an operational process-noise covariance Q of a Kalman filter is temporarily replaced with a substantially greater interim process-noise covariance Q. This replacement increases the weight given to the most recent attitude measurements and hastens the reduction of attitude errors and gyroscope bias errors. The error effect of the substituted gyroscopes is reduced and the absolute-attitude sensors are not driven out of their capture range. In another method embodiment, this replacement is preceded by the temporary replacement of an operational measurement-noise variance R with a substantially larger interim measurement-noise variance R to reduce transients during the gyroscope substitutions.
    Type: Grant
    Filed: October 28, 2001
    Date of Patent: January 20, 2004
    Assignee: The Boeing Company
    Inventors: Rongsheng Li, Jeffrey A. Kurland, Alec M. Dawson, Yeong-Wei A. Wu, David S. Uetrecht
  • Publication number: 20030222816
    Abstract: Methods and structures are provided for reducing pointing errors &zgr; of satellite antennas and for generating broad field-of-view satellite attitude acquisition patterns. In one method embodiment, satellite transmit beams have estimated pointing attitudes &bgr; and are transmitted to overlap on a ground-based receiving terminal which has a known terminal location &lgr; and which measures received signal strengths &agr;. Pointing errors &zgr; of the transmit beams are then determined from the estimated pointing attitudes &bgr;, the terminal location &lgr; and the signal strengths &agr; and the pointing errors &zgr; are subsequently reduced by revising the pointing attitudes &bgr;. Other method embodiments utilize known signal-strength functions and antenna signals with known signal parameters such as frequencies and/or modulations.
    Type: Application
    Filed: June 3, 2002
    Publication date: December 4, 2003
    Applicant: The Boeing Company
    Inventors: Ketao Liu, Richard Fowell, Yeong-Wei A. Wu, Rongsheng Li
  • Publication number: 20030171855
    Abstract: Methods and structures are provided that enhance attitude control during gyroscope substitutions by insuring that a spacecraft's attitude control system does not drive its absolute-attitude sensors out of their capture ranges. In a method embodiment, an operational process-noise covariance Q of a Kalman filter is temporarily replaced with a substantially greater interim process-noise covariance Q. This replacement increases the weight given to the most recent attitude measurements and hastens the reduction of attitude errors and gyroscope bias errors. The error effect of the substituted gyroscopes is reduced and the absolute-attitude sensors are not driven out of their capture range. In another method embodiment, this replacement is preceded by the temporary replacement of an operational measurement-noise variance R with a substantially larger interim measurement-noise variance R to reduce transients during the gyroscope substitutions.
    Type: Application
    Filed: October 28, 2001
    Publication date: September 11, 2003
    Applicant: BOEING COMPANY
    Inventors: Rongsheng Li, Jeffrey A. Kurland, Alec M. Dawson, Yeong-Wei A. Wu, David S. Uetrecht
  • Patent number: 6615117
    Abstract: A method and apparatus for calibrating rate sensor measurements to compensate for rate sensor scale factor non-linearities. An outer loop compensator compares current rate sensor scale factor estimates with the current scale factor non-linearity compensation, and deviations from the current non-linearity compensation are corrected in an updated compensation.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: September 2, 2003
    Assignee: The Boeing Company
    Inventors: Rongsheng Li, Yeong-Wei Wu, David L. Augenstein
  • Patent number: 6595469
    Abstract: Attitude determination and control systems are provided that combine attitude measurements from all spacecraft payloads to determine a master attitude estimate for a master payload and relative slave attitude estimates for the remaining slave payloads. These estimates are then used to control the attitudes of spacecraft elements that correct the absolute and relative attitude errors. These systems significantly enhance attitude accuracy when compared to systems that realize independent payload estimates, determine payload attitudes. These systems also provide significant processing advantages (e.g., simpler algorithms, reduced data throughput and slower processing rate).
    Type: Grant
    Filed: October 28, 2001
    Date of Patent: July 22, 2003
    Assignee: The Boeing Company
    Inventors: Rongsheng Li, Yeong-Wei A. Wu, Hanching Grant Wang
  • Patent number: 6588708
    Abstract: The present invention is directed to spacecraft that have, for any reason, lost the spacecraft's service attitude that permits it to carry out the service operations for which it was designed. The invention provides methods and structures for acquiring and determining a power-safe attitude (i.e., one in which wing current is sufficient to support the spacecraft's housekeeping operations) from which the spacecraft can be subsequently returned to a service attitude. The methods are particularly useful because they a) require only a single star tracker for sensing attitude, comprise simple maneuvers, and typically acquire a power-safe attitude that does not significantly differ from the spacecraft's service attitude to thereby reduce the spacecraft's return-to-service time.
    Type: Grant
    Filed: January 29, 2001
    Date of Patent: July 8, 2003
    Assignee: The Boeing Company
    Inventors: Grant Wang, Yeong-Wei Wu, Rongsheng Li, David D. Needelman
  • Patent number: 6566640
    Abstract: A method and apparatus for post processing a star tracker measurement to remove a systematic error characterizable at least in part by a pixel phase is disclosed. The method comprises the steps of computing the pixel phase along a first axis from a measured star position and a star tracker characteristic, computing a first axis error correction according to the computed pixel phase, and computing a compensated first axis star tracker measurement according to the measured star position and the first axis error correction.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: May 20, 2003
    Assignee: The Boeing Company
    Inventors: Yeong-Wei Wu, Rongsheng Li
  • Publication number: 20030093194
    Abstract: A method and apparatus for calibrating rate sensor measurements to compensate for rate sensor scale factor non-linearities. An outer loop compensator compares current rate sensor scale factor estimates with the current scale factor non-linearity compensation, and deviations from the current non-linearity compensation are corrected in an updated compensation.
    Type: Application
    Filed: November 13, 2001
    Publication date: May 15, 2003
    Applicant: THE BOEING COMPANY
    Inventors: Rongsheng Li, Yeong-Wei Wu, David L. Augenstein
  • Publication number: 20030080255
    Abstract: Attitude determination and control systems are provided that combine attitude measurements from all spacecraft payloads to determine a master attitude estimate for a master payload and relative slave attitude estimates for the remaining slave payloads. These estimates are then used to control the attitudes of spacecraft elements that correct the absolute and relative attitude errors. These systems significantly enhance attitude accuracy when compared to systems that realize independent payload estimates. determine payload attitudes. These systems also provide significant processing advantages (e.g., simpler algorithms, reduced data throughput and slower processing rate).
    Type: Application
    Filed: October 28, 2001
    Publication date: May 1, 2003
    Applicant: THE BOEING COMPANY
    Inventors: Rongsheng Li, Yeong-Wei A. Wu, Hanching Grant Wang
  • Publication number: 20030057354
    Abstract: A method and apparatus for post processing a star tracker measurement to remove a systematic error characterizable at least in part by a pixel phase is disclosed. The method comprises the steps of computing the pixel phase along a first axis from a measured star position and a star tracker characteristic, computing a first axis error correction according to the computed pixel phase, and computing a compensated first axis star tracker measurement according to the measured star position and the first axis error correction.
    Type: Application
    Filed: September 24, 2001
    Publication date: March 27, 2003
    Applicant: THE BOEING COMPANY
    Inventors: Yeong-Wei Wu, Rongsheng Li