Measurement fault detection

• US 6,691,066 B1
• Filed: 08/28/2001
• Issued: 02/10/2004
• Est. Priority Date: 08/28/2000
• Status: Expired due to Term

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Brodie, Keith Jacob
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): LE, JOHN H
• Application Number:
  US09/942,060
• Time in Patent Office: 896 Days
• Field of Search: 702/59, 702/97, 702/116, 702/183, 702/185, 702/190, 701/213, 701/215, 701/216, 342/357.02, 342/358
• US Class Current: 702/185
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/22 Multipath-related issues
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering

Abstract

The present invention discloses a method and an apparatus for improving measurement fault detection in a sequential measurement processing estimator, and is particularly applied to Global Positioning Receivers.

Claims

1. A method of fault detection, comprising:

recording a plurality of measurements, each measurement having an associated measurement time;

sorting the plurality of measurements, wherein the sort of the plurality of measurements is performed in order of increasing fault probability;

propagating a state matrix and a covariance matrix forward from the first time to a time of the measurement having a highest fault probability;

processing the measurement having the highest fault probability first, wherein processing comprises;

updating the state matrix and the covariance matrix at a time of the measurement having the highest fault probability; and

propagating the state matrix and the covariance matrix backwards in time to a time of a measurement with a next highest fault probability;

continuing processing until all measurements have been processed; and

propagating the state matrix and the covariance matrix forward from a last measurement time to a reporting time.

2. The method of claim 1 applied to a Global Positioning System (GPS) receiver.

3. The method of claim 2, wherein the propagating the state matrix and covariance matrix backwards in time further comprises subtracting a process noise matrix from a state error covariance matrix.

4. The method of claim 3, wherein the measurements are non-simultaneous.