Inertial measurement unit for aircraft

• US 7,962,285 B2
• Filed: 01/28/2008
• Issued: 06/14/2011
• Est. Priority Date: 10/22/1997
• Status: Expired due to Fees

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Intelligent Technologies International, Inc.
• Inventors: Breed, David S.
• Primary Examiner(s): Zanelli; Michael J.
• Application Number:
  US12/020,652
• Publication Number:
  US 20080154495A1
• Time in Patent Office: 1,233 Days
• Field of Search: 701/221
• US Class Current: 701/216
• CPC Class Codes: G01C 21/12 executed aboard the object being navigated; Dead reckoning
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence

Abstract

System for determining position of a vehicle includes an integral inertial measurement unit (IMU) including accelerometers and gyroscopes for providing raw data about movement of the vehicle and a correction unit coupled to the IMU and arranged to receive and/or derive positional corrections and the raw data from the IMU and generate accurate positional information about the vehicle based on the raw data and positional corrections. A navigation system is coupled to the correction unit and receives and acts upon the positional information of the vehicle provided by the correction unit. The IMU may be a MEMS-packaged IMU and integrated with the correction unit in combination with one another. A map database may be coupled to the navigation system which would receive information about a travel lane the vehicle is travelling on and could guide an operator of the vehicle based on the accurate positional information and travel lane information.

Claims

1. A system for determining position of a vehicle, comprising:

a MEMS, integral inertial measurement unit (IMU) including a plurality of MEMS accelerometers and MEMS gyroscopes for providing raw data about movement of the vehicle;

a GPS receiver for receiving vehicle positional data; and

a correction unit coupled to said IMU and arranged to derive positional corrections to the raw data from said MEMS accelerometers and MEMS gyroscopes and output positional information,

said correction unit comprising a processor containing a Kalman filter and being arranged to improve the accuracy of said MEMS accelerometers and MEMS gyroscopes based on the vehicle positional data using the Kalman filter.

2. The system of claim 1, wherein said IMU and said correction unit are integrated in combination with one another.

3. The system of claim 1, further comprising:

a navigation system coupled to said correction unit for receiving and acting upon the positional information of the vehicle provided by said correction unit; and

a map database coupled to said navigation system, said navigation system being arranged to receive information about a travel lane the vehicle is travelling on and guiding an operator of the vehicle based on the positional information and travel lane information.

4. The system of claim 1, wherein said correction unit is arranged to communicate with satellites to receive positional corrections therefrom.

5. The system of claim 1, wherein said correction unit is arranged to communicate with ground base stations to receive positional corrections therefrom.

6. The system of claim 1, wherein the vehicle is an airplane.

7. The system of claim 1, further comprising a DGPS receiver for receiving differential correction signals.

8. The system of claim 1, wherein said correction unit is arranged to negate real-time influences of physical characteristics on said accelerometers and said gyroscopes after installation of said IMU on the vehicle.

9. The system of claim 1, further comprising at least one of a device for measuring at least one of the downward direction of the earth'"'"'s magnetic field, a flux gage compass, a magnetic compass, a gravity sensor, a speedometer, an odometer, an anti-lock brake sensor, and a wheel speed sensor for providing input to said Kalman filter.

10. The system of claim 1, wherein said Kalman filter is arranged to determine and apply a correction for each of said accelerometers and said gyroscopes.

11. The system of claim 1, wherein said IMU comprises three accelerometers and three gyroscopes.

12. A system for determining position of a vehicle, comprising:

a single integrated unit including a MEMS-packaged integral inertial measurement unit (IMU), a GPS receiver for receiving vehicle positional data, and a correction unit coupled to said IMU, said IMU including a plurality of MEMS accelerometers and MEMS gyroscopes for providing raw data about movement of the vehicle, said correction unit being arranged to derive positional corrections to the raw data from said MEMS accelerometers and MEMS gyroscopes and output positional information; and

said correction unit comprising a processor containing a Kalman filter and being arranged to improve the accuracy of said MEMS accelerometers and MEMS gyroscopes based on the vehicle positional data using the Kalman filter.

13. The system of claim 12, further comprising:

a navigation system coupled to said correction unit for receiving and acting upon the positional information of the vehicle provided by said correction unit; and

a map database coupled to said navigation system, said navigation system being arranged to receive information about a travel lane the vehicle is travelling on and guiding an operator of the vehicle based on the accurate positional information and travel lane information.

14. The system of claim 12, wherein said correction unit is arranged to communicate with satellites to receive positional corrections therefrom and/or communicate with ground base stations to receive positional corrections therefrom.

15. The system of claim 12, further comprising a DGPS receiver for receiving differential correction signals.

16. The system of claim 12, further comprising at least one of a device for measuring at least one of the downward direction of the earth'"'"'s magnetic field, a flux gage compass, a magnetic compass, a gravity sensor, a speedometer, an odometer, an anti-lock brake sensor, and a wheel speed sensor for providing input to said Kalman filter.

17. The system of claim 12, wherein said Kalman filter is arranged to determine and apply a correction for each of said MEMS accelerometers and said MEMS gyroscopes.

18. The system of claim 12, wherein the vehicle is an airplane.