Remote velocity sensor slaved to an integrated GPS/INS

• US 20040036650A1
• Filed: 08/26/2002
• Published: 02/26/2004
• Est. Priority Date: 08/26/2002
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Morgan, Kenneth S.
• Granted Patent: US 6,831,599 B2
• Time in Patent Office: Days
• US Class Current: 342/357.14
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01S 13/9019 Auto-focussing of the SAR signals
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A unit is configured to provide acceleration, velocity, and position information for one or more points on a vehicle. The unit includes an integrated global positioning satellite system (GPS)/inertial navigation system (INS) and at least one remote velocity sensor. The remote velocity sensors include three orthogonal accelerometers and a digital signal processor configured to receive signals from the accelerometers. The remote velocity sensors are mounted at points on the vehicle where acceleration, velocity and position are to be determined. Data from the sensors is slaved to data from the integrated GPS/INS, and the unit is configured to transform data from the sensors to a navigation frame utilizing a sensor frame to navigation frame attitude matrix.

Claims

1. A unit configured to provide acceleration, velocity, and position information for one or more points on a vehicle, said unit comprising:

an integrated global positioning satellite system (GPS)/inertial navigation system (INS); and

at least one remote velocity sensor, said sensors comprising three orthogonal accelerometers, and a digital signal processor configured to receive signals from said accelerometers, said sensor mounted at a location on the vehicle where acceleration, velocity and position are to be determined, data from said sensor slaved to data from said integrated GPS/INS, said unit configured to transform data from said sensor to a navigation frame utilizing a sensor frame to navigation frame attitude matrix.

2. A unit according to claim 1 wherein said unit is configured to combine a velocity from said sensor with a velocity from said integrated GPS/INS to provide a velocity at said remote velocity sensor with respect to a navigation frame of the vehicle.

3. A unit according to claim 2 wherein said unit is configured to integrate the velocity at said remote velocity sensor to provide a position with respect to a navigation frame of the vehicle.

4. A unit according to claim 1 wherein position, velocity and attitude data is sent from said integrated GPS/INS to said remote velocity sensor.

5. A unit according to claim 4 further configured to provide acceleration, velocity and position data, based upon outputs of said accelerometers combined with position, velocity and attitude data received from said integrated GPS/INS.

6. A unit according to claim 1 wherein delta velocity data is sent from said remote velocity sensor to said integrated GPS/INS.

7. A unit according to claim 6 further configured to provide acceleration, velocity and position data, based upon delta velocity data combined with position, velocity and attitude data as determined by said integrated GPS/INS.

8. A unit according to claim 1 wherein said unit comprises a fusion filter, said filter configured to provide a corrected position and velocity of said remote velocity sensor based upon remote velocity sensor generated position and velocity data and an estimated position and velocity of said remote velocity sensor determined by said GPS/INS.

9. A unit according to claim 8 wherein said fusion filter is configured to:

determine a difference between a velocity as measured by said GPS/INS and transformed to a position of said remote velocity sensor and a velocity generated by said remote velocity sensor; and

utilize the difference to remove low frequency errors within the velocity generated by said remote velocity sensor.

10. A unit according to claim 8 wherein said fusion filter is configured to:

determine a difference between a position as measured by said GPS/INS and transformed to a position of said remote velocity sensor and a position generated by said remote velocity sensor; and

utilize the difference to remove low frequency errors within the position generated by said remote velocity sensor.

11. A unit according to claim 1 wherein the sensor frame to navigation frame attitude matrix is transmitted from said integrated GPS/INS to said digital signal processor.

12. A unit according to claim 1 wherein delta velocities from said remote velocity sensor are transformed utilizing the sensor frame to navigation frame attitude matrix within said integrated GPS/INS.

13. A unit according to claim 1 wherein said remote velocity sensor comprises input and output capability to receive position, velocity and attitude data from said integrated GPS/INS.

14. A method for removing a low frequency drift in data from a remote velocity sensor, the remote velocity sensor including a digital signal processor (DSP) and three orthogonal accelerometers providing signals to the DSP which generates the data, the remote velocity sensor configured for communication with an integrated global positioning satellite system (GPS)/inertial navigation system (INS), said method comprising:

receiving data from the remote velocity sensor;

receiving data from the integrated GPS/INS; and

transforming the data from the remote velocity sensor data to the data from the integrated GPS/INS using a sensor frame to navigation frame attitude matrix.

15. A method according to claim 14 further comprising determining a velocity at the remote velocity sensor position with respect to the navigation frame.

16. A method according to claim 15 wherein determining a velocity comprises:

determining a difference between a velocity as measured by the GPS/INS and transformed to a position of the remote velocity sensor and a velocity as measured by the remote velocity sensor; and

utilizing the difference to remove low frequency errors within the data generated by the remote velocity sensor.

17. A method according to claim 15 further comprising integrating the velocity to determine a position with respect to the remote velocity sensor.

18. A method according to claim 14 wherein receiving data from the remote velocity sensor comprises forming acceleration, velocity and position outputs in the digital signal processor of the remote velocity sensor based upon accelerometer outputs.

19. A method according to claim 14 wherein transforming the data comprises:

transmitting the attitude matrix from the integrated GPS/INS to the remote velocity sensor; and

sending position, velocity and attitude data from the integrated GPS/INS to the remote velocity sensor.

20. A method according to claim 14 wherein transforming the data comprises transmitting high frequency delta velocities to the integrated GPS/INS from the remote velocity sensor.

21. A filter configured to:

receive global positioning satellite system (GPS)/inertial navigation system (INS) position, velocity, and attitude data and remote velocity sensor (RVS) position and velocity data;

integrate the GPS/INS velocity over a filter period;

integrate the RVS velocity over the filter period;

form a difference between the RVS velocity integration and the GPS/INS integration; and

correct a RVS velocity solution based on the difference.

22. A filter according to claim 21 further configured to:

form a difference between a RVS velocity position and GPS/INS position; and

correct a RVS position solution based on the difference.

23. A filter according to claim 22 configured to:

propagate filter error state estimates and uncertainties; and

update the error state estimates and uncertainties based upon the differences in velocity and position.