Patent · US Expired

Breaklock detection system and method

US6799138B2 · kind B2 · utility

4Cited by
4References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 30, 2002
Grant dateSep 28, 2004
Priority date
Expiry dateApr 30, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S13/723
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A tracking system controls an aimed device (32) to keep it aimed at a target (34). A control system (10) determines when the tracker has lost its lock on the target (34) by comparing the target's instantaneous acceleration with its median acceleration. When the difference exceeds a predetermined threshold, the system searches backwards through a chronological buffer until it finds position data which antedate the receipt of inaccurate position data from the tracker. A second-order filter such as a Kalman filter is used to provide estimated target states. The difference between a time updated output from the second-order filter (16) and the present measured state from the tracking device is low pass filtered to provide a measurement of the instantaneous acceleration of the target. The buffer (20) stores position, velocity, and median acceleration values covering a span of time at least about twice as long as the time required to determine that a breaklock has occurred.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.