Methods and systems for data link front end filters for sporadic updates

• US 7,720,577 B2
• Filed: 05/17/2006
• Issued: 05/18/2010
• Est. Priority Date: 05/17/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Neff, Michael G., Cheng, Shirley N., Johnson, Ted L.
• Primary Examiner(s): Camby; Richard M.
• Application Number:
  US11/383,919
• Publication Number:
  US 20070271032A1
• Time in Patent Office: 1,462 Days
• Field of Search: 701/2, 701/3, 701/4, 701/11, 701200-213, 701/26, 701/223, 244/181, 244/75.1, 244/190, 342/370, 342/372
• US Class Current: 701/2
• CPC Class Codes: G01S 13/66 Radar-tracking systems; Analogous systems
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering

Abstract

Systems and methods having front end filters for data links for improved tracking of moving objects are disclosed. In one embodiment, a method includes sensing at least one characteristic of a moveable object using a sensor of an acquisition system, and sensing at least one characteristic of the moveable object using an auxiliary sensor. A data link update is transmitted from the auxiliary sensor to the acquisition system, and the data link update is conditioned to provide composite likelihood. The conditioning includes differencing the data link update and at least one predicted characteristic of the moveable object to produce at least one residual (e.g. using a plurality of Kalman filters). A viewing direction of the sensor may be adjusted based at least in part on the composite likelihood. In another embodiment, residuals are projected along sensor line of sight to form a multi-modal non-Gaussian composite likelihood.

Claims

1. A method of tracking a moveable object, comprising:

sensing at least one characteristic of the moveable object using a sensor of an acquisition system;

sensing at least one characteristic of the moveable object using an auxiliary sensor;

transmitting a data link update from the auxiliary sensor to the acquisition system;

conditioning the data link update to provide a composite likelihood, wherein the conditioning includes;

differencing the data link update and at least one predicted characteristic of the moveable object to produce at least one residual; and

determining the composite likelihood based on the at least one residual; and

adjusting a viewing direction of the sensor based at least in part on the composite likelihood resulting from the conditioning of the data link update.

2. The method of claim 1, wherein conditioning the data link update includes receiving the data link update into a plurality of Kalman filters, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and configured to output the at least one predicted characteristic.

3. The method of claim 1, wherein the conditioning includes:

receiving the data link update into a plurality of Kalman filters;

predicting at least one characteristic using the plurality of Kalman filters;

determining residuals using the at least one predicted characteristic and the data link update; and

determining the composite likelihood based at least in part on the residuals.

4. The method of claim 3, wherein the conditioning further includes:

projecting a plurality of covariance matrices along a sensor line of sight; and

weighting the plurality of covariance matrices;

and wherein determining the composite likelihood includes combining the weighted covariance matrices.

5. The method of claim 3, wherein conditioning the data link update includes receiving the data link update into a plurality of Kalman filters, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and configured to output the at least one predicted characteristic.

6. The method of claim 1, wherein the conditioning includes:

receiving the data link update into a plurality of Kalman filters coupled in parallel, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and configured to output the at least one predicted characteristic;

predicting at least one characteristic using the plurality of Kalman filters;

determining residuals using the at least one predicted characteristic and the data link update;

projecting a plurality of covariance matrices along a sensor line of sight;

weighting the plurality of covariance matrices; and

wherein determining the composite likelihood includes combining the weighted covariance matrices.

7. The method of claim 1, further comprising translating the sensor into a position configured to view the moveable object using a moveable platform, the moveable platform including at least one of an unmanned aircraft, a manned aircraft, a land-based platform, a sea-based platform, and a space-based platform.

8. The method of claim 1, wherein sensing at least one characteristic of the moveable object using an auxiliary sensor includes sensing at least one characteristic of the moveable object using at least one of an unmanned aircraft, a manned aircraft, a ground-based vehicle, a space-based vehicle, and an operator on the ground with a targeting designating device.

9. The method of claim 1, wherein adjusting a viewing direction of the sensor based at least in part on the composite likelihood includes merging the composite likelihood with other moving object information using a data fusion manager, and generating a sensor control signal based at least in part on the composite likelihood to adjust the viewing direction of the sensor.

10. One or more computer-readable media comprising computer executable instructions that, when executed, direct a tracking system to:

sense at least one characteristic of a moveable object using a sensor of an acquisition system;

sense at least one characteristic of the moveable object using an auxiliary sensor;

transmit a data link update from the auxiliary sensor to the acquisition system;

condition the data link update to provide a composite uncertainty probability, including;

difference the data link update and at least one predicted characteristic of the moveable object to produce at least one residual; and

determine the composite likelihood based on the at least one residual; and

adjust the position of the sensor based at least in part on the composite likelihood resulting from the conditioning of the data link update.

11. The one or more computer-readable media of claim 10, wherein condition the data link update includes receive the data link update into a plurality of Kalman filters, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and configured to output the at least one predicted characteristic.

12. The one or more computer-readable media of claim 10, wherein condition the data includes:

receive the data link update into a plurality of Kalman filters;

predict at least one characteristic using the plurality of Kalman filters;

determine residuals using the at least one predicted characteristic and the data link update; and

determine the composite likelihood based at least in part on the residuals.

13. The one or more computer-readable media of claim 12, wherein condition the data further includes:

project a plurality of covariance matrices along a sensor line of sight; and

weight the plurality of covariance matrices;

and wherein determine the composite likelihood includes combine the weighted covariance matrices.

14. The one or more computer-readable media of claim 10, wherein condition the data further includes:

receive the data link update into a plurality of Kalman filters coupled in parallel, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and configured to output the at least one predicted characteristic;

predict at least one characteristic using the plurality of Kalman filters;

determine residuals using the at least one predicted characteristic and the data link update;

project a plurality of covariance matrices along a sensor line of sight; and

weight the plurality of covariance matrices;

and wherein determine the composite likelihood includes combine the weighted covariance matrices.

15. A system for tracking a moveable object, comprising:

a sensor configured to sense at least one characteristic of the moveable object;

a communication component configured to receive a data link update; and

a control component operatively coupled to the communication component and to the sensor, the control component including a data conditioner configured to condition the data link update to provide a composite likelihood, including;

difference the data link update and at least one predicted characteristic of the moveable object to produce at least one residual; and

determine the composite likelihood based on the at least one residual;

and wherein the control component is further configured to transmit a control signal to adjust a viewing direction of the sensor based at least in part on the composite likelihood.

16. The system of claim 15, wherein the control component includes a plurality of Kalman filters, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and being configured to receive at least a portion of the data link update, and to output the at least one predicted characteristic.

17. The system of claim 15, wherein the data conditioner is further configured to condition the data link update, including:

receive the data link update into a plurality of Kalman filters;

predict at least one characteristic using the plurality of Kalman filters;

determine residuals using the at least one predicted characteristic and the data link update; and

determine the composite likelihood based at least in part on the residuals.

18. The system of claim 17, wherein the data conditioner is further configured to condition the data link update, including:

project a plurality of covariance matrices along a sensor line of sight; and

weight the plurality of covariance matrices;

and wherein determine the composite likelihood includes combine the weighted covariance matrices.

19. The system of claim 15, wherein the data conditioner is further configured to condition the data link update, including:

receive the data link update into a plurality of Kalman filters coupled in parallel, each Kalman filter being tuned to a specific combination of measurement error statistics and position error statistics, and configured to output the at least one predicted characteristic;

predict at least one characteristic using the plurality of Kalman filters;

determine residuals using the at least one predicted characteristic and the data link update;

project a plurality of covariance matrices along a sensor line of sight; and

weight the plurality of covariance matrices;

and wherein determine the composite likelihood includes combine the weighted covariance matrices.

20. The system of claim 15, further comprising a moveable platform configured to support the sensor, the communication component, and the control component, the moveable platform being configured to translate the sensor in a location configured to view the moveable object, the moveable platform including at least one of an unmanned aircraft, a manned aircraft, a land-based platform, a sea-based platform, and a space-based platform.