Navigation system with rapid GNSS and inertial initialization

• US 9,182,237 B2
• Filed: 02/12/2015
• Issued: 11/10/2015
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: Novatel Incorporated (Hexagon AB)
• Original Assignee: Novatel Incorporated (Hexagon AB)
• Inventors: Morin, Kristian, Bobye, Michael, Kennedy, Sandra
• Primary Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US14/620,392
• Publication Number:
  US 20150268047A1
• Time in Patent Office: 271 Days
• Field of Search: 701/300, 701/468, 701/469, 701/472, 701/479, 701/480, 703/2, 702150-153, 348/113, 348/118, 342/357.73, 342/357.62, 342/357.39, 342/357.34, 342/357.3
• US Class Current: 1/1
• CPC Class Codes: G01C 21/1652 with ranging devices, e.g. LIDAR or RADAR
• CPC Class Codes: G01C 21/1656 with passive imaging devices, e.g. cameras
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/51 Relative positioning
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G06F 17/13 Differential equations using digital differential analysers G06F7/64
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source
• CPC Class Codes: H04N 7/185 from a mobile camera, e.g. for remote control

Abstract

A navigation system for use with moving vehicles includes target points proximate to a rendezvous site located on a first moving vehicle. One or more transmitters broadcast target point positioning information. A navigation unit on a second moving vehicle utilizes a camera to capture images that include the target points or a detector system that emits one or more beams to the target points. The navigation unit determines the relative position and orientation of the rendezvous site at the second vehicle. The navigation unit utilizes the relative position and orientation and an absolute position and orientation of the rendezvous site calculated from the target position information and calculates an absolute position and orientation corresponding to the second vehicle. The navigation unit then initializes its component inertial subsystem using a local position and orientation that are based on the calculated absolute position and orientation of the second vehicle.

Claims

1. An inertial/global navigation satellite system (GNSS) navigation system comprising:

on a first moving vehicle

a constellation of target points proximate to a rendezvous site;

one or more transmitters that transmit target position information corresponding to the respective target points;

on a second moving vehicle

a detector system;

a receiver that receives the transmitted target position information; and

a navigation unit including

a detector subprocessor that determines calculated relative positions and orientations of the target points based on distance information indicating a distance between the detection system and each respective target point determined utilizing one or more beams emitted by the detector system,

a GNSS subsystem including a GNSS receiver,

an inertial navigation (INS) subsystem including an inertial measurement unit, and

one or more processors configured to calculate an absolute position and orientation corresponding to the second vehicle based on the calculated relative position of the rendezvous site and the received target position information, the one or more processors providing the calculated absolute position and orientation corresponding to the second vehicle to at least the INS subsystem;

the INS subsystem determining a local position and orientation for use in an initialization process based on the calculated absolute position and orientation corresponding to the second vehicle.

2. The inertial/GNSS navigation system of claim 1, wherein the detector system includes a light sensor that emits a beam of light that reflects from each respective target.

3. The inertial/GNSS navigation system of claim 2, wherein the detector subprocessor determines the distance based on at least one of a rate of travel of the beam of light, an angle of reflection of the beam of light, and a time it takes for the beam of light to reflect back to the detector system.

4. The inertial/GNSS navigation system of claim 1, wherein the detector system includes an acoustical sensor that emits an acoustical wave that reflects from each respective target.

5. The inertial/GNSS navigation system of claim 4, wherein the detector subprocessor determines the distance based on at least one of a rate of travel of the acoustical wave, an angle of reflection of the acoustical wave, and a time it takes for the acoustical wave to reflect back to the detector system.

6. The inertial/GNSS navigation system of claim 1, wherein the detector system includes an RF sensor that emits an RF signal that reflects from each respective target.

7. The inertial/GNSS navigation system of claim 6, wherein the detector subprocessor determines the distance based on at least one of a rate of travel of the RF signal, an angle of reflection of the RF signal, and a time it takes for the RF signal to reflect back to the detector system.

8. The inertial/GNSS navigation system of claim 1, wherein the detector system includes an infrared sensor that emits an infrared signal that reflects from each respective target.

9. The inertial/GNSS navigation system of claim 8, wherein the detector subprocessor determines the distance based on at least one of a rate of travel of the infrared signal, an angle of reflection of the infrared signal, and a time it takes for the infrared signal to reflect back to the detector system.

10. The inertial/GNSS navigation system of claim 1, wherein the GNSS subsystem uses the received target position information to aid in initialization.

11. The inertial/GNSS navigation system of claim 1, wherein the target points are distinguishable from one and other by one or more of shape, patterns, or markings.

12. The inertial/GNSS navigation system of claim 1, wherein the target position information for a given target point includes a global position, a target point identifier, and a time tag.

13. The inertial/GNSS navigation system of claim 1 wherein the constellation consists of at least four target points.

14. The inertial/GNSS navigation system of claim 1 wherein the navigation unit provides navigation information to a steering device on the second vehicle.

15. A method comprising:

transmitting, by one or more transmitters on a first vehicle, target position information corresponding to each respective target point of a constellation of target points proximate to a rendezvous site on a first moving vehicle;

receiving, by a receiver on a second vehicle, the transmitted target information;

determining, by a detector system on the second vehicle, calculated relative positions and orientations of the target points based on distance information indicating a distance between the detection system and each respective target point determined utilizing one or more beams emitted by the detector system;

calculating, by one or more processors on the second vehicle, an absolute position and orientation corresponding to the second vehicle based on the calculated relative position of the rendezvous site and the received target position information; and

providing, by the one or more processors, the calculated absolute position and orientation corresponding to the second vehicle to at least an inertial navigation (INS) subsystem on the second vehicle, where the INS subsystem utilizes the calculated absolute position and orientation corresponding to the second vehicle to determine a local position and orientation for use in an initialization process.

16. The method of claim 15, wherein the detector system includes a light sensor that emits a beam of light that reflects from each respective target.

17. The method of claim 16, wherein the detector system determines the distance based on at least one of a rate of travel of the beam of light, an angle of reflection of the beam of light, and a time it takes for the beam of light to reflect back to the detector system.

18. The method of claim 15, wherein the detector system includes an acoustical sensor that emits an acoustical wave that reflects from each respective target.

19. The method of claim 18, wherein the detector system determines the distance based on at least one of a rate of travel of the acoustical wave, an angle of reflection of the acoustical wave, and a time it takes for the acoustical wave to reflect back to the detector system.

20. The method of claim 15, wherein the detector system includes an RF sensor that emits an RF signal that reflects from each respective target.

21. The method of claim 20, wherein the detector system determines the distance based on at least one of a rate of travel of the RF signal, an angle of reflection of the RF signal, and a time it takes for the RF signal to reflect back to the detector system.

22. The method of claim 15, wherein the detector system includes an infrared sensor that emits an infrared signal that reflects from each respective target.

23. The method of claim 22, wherein the detector subprocessor determines the distance based on at least one of a rate of travel of the infrared signal, an angle of reflection of the infrared signal, and a time it takes for the infrared signal to reflect back to the detector system.