Estimating position and orientation of an underwater vehicle based on correlated sensor data

• US 8,965,682 B2
• Filed: 10/25/2011
• Issued: 02/24/2015
• Est. Priority Date: 10/25/2010
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Tangirala, Sekhar C., Feldman, I, Walter K., Debrunner, Christian H.
• Primary Examiner(s): Nguyen, Kim T
• Application Number:
  US13/280,536
• Publication Number:
  US 20120101715A1
• Time in Patent Office: 1,218 Days
• Field of Search: 701/400, 701/408, 701/412, 701/445, 701/468, 701/523
• US Class Current: 701/408
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G01C 21/1656 with passive imaging devices, e.g. cameras

Abstract

A method and system are described that can be used for combining two sources of position and orientation (pose) information where the information from one source is correlated with the information from the other and the sources produce information at differing rates. For example, the method and system allow for estimating position and orientation (pose) of an underwater vehicle relative to underwater structures by combining pose information computed from a 3D imaging sonar with pose information from a vehicle navigation system. To combine the information from the two sources, a determination is made as to whether to generate a forward prediction of the pose estimate of one of the sources relative to the other, and generating the forward prediction if needed. An updated pose of the underwater vehicle is determined based on the fused pose estimate, and which is used for vehicle guidance and control.

Claims

1. A method of estimating position and orientation of an underwater vehicle comprising:

receiving, by a processor, pose data from one source, the one source being a vehicle navigation system;

receiving, by a processor, pose data from another source being an image sensor-base source different from the vehicle navigation system;

determining a fused pose estimate using a processor, the determining comprising determining a forward prediction of the pose data received from the image sensor-based source based on a forward propagation of the pose data from the image sensor-based source relative to the pose data from the vehicle navigation system and combining, using a processor, the pose data from the vehicle navigation system and the forward prediction of the pose data from the image sensor-based source, the combination resulting in the fused pose estimate; and

estimating, using a processor, an updated pose of the underwater vehicle based on the fused pose estimate.

2. The method of claim 1, wherein the vehicle navigation system is an inertial navigation system of the underwater vehicle that is configured to provide an estimate of the pose of the underwater vehicle.

3. The method of claim 1, wherein the image sensor-based source is a three dimensional sonar based sensor that is configured to provide a three dimensional image of an underwater structure and an estimate of the pose of the underwater vehicle.

4. The method of claim 1, wherein the step of estimating an updated pose comprises correcting drift in the vehicle navigation system, the correcting drift occurring at a period determined by a correlation time of the fused pose estimate.

5. The method of claim 1, further comprising reinitializing the image sensor-based source, using a processor, to generate a different pose data that is more accurate and consistent with a current fused pose estimate, the reinitializing comprises performing failure detection processing.

6. The method of claim 1, further comprising resetting a pose of the vehicle navigation system, using a processor, based on the fused pose estimate.

7. The method of claim 1, wherein the underwater vehicle is one of an autonomous underwater vehicle or a remotely operated vehicle.

8. The method of claim 1, further comprising correlating, using a processor, the pose data from the image sensor-based source with the pose data front the vehicle navigation system.

9. A system for estimating position and orientation of an underwater vehicle comprising:

a sensor onboard an underwater vehicle, the sensor is configured to direct toward an underwater structure an acoustic sonar wave to be reflected back to be the sensor, and configured to receive the reflected acoustic sonar wave to be processed to produce an image sensor-based pose estimate;

a vehicle navigation system onboard the underwater vehicle, the vehicle navigation system is configured to provide an estimate of pose of the underwater vehicle

a data storage onboard the underwater vehicle that is configured to receive the image sensor-based pose estimate; and

a data processor onboard the underwater vehicle, the data processor is configured to receive both the image sensor-based pose estimate and the estimate of pose from the vehicle navigation system,

the data processor is configured to determine a fused pose estimate, the fused pose estimate is determined by the data processor being configured to determine a forward prediction of the image sensor-based pose estimate based on a forward propagation of the image sensor-based pose estimate relative to the estimate of pose from the vehicle navigation system, and being configured to combine the estimate of pose from the vehicle navigation system and the forward prediction of the image sensor-based pose estimate, where the combination results in the fused pose estimate, and

the data processor is configured to estimate an updated pose of the underwater vehicle based on the fused pose estimate.

10. The system of claim 9, wherein the image sensor-based pose estimate provided by the sensor is correlated with the pose estimate provided by the vehicle navigation system.