INERTIAL SENSOR AIDED HEADING AND POSITIONING FOR GNSS VEHICLE NAVIGATION

• US 20120173195A1
• Filed: 12/01/2011
• Published: 07/05/2012
• Est. Priority Date: 12/03/2010
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: OPSHAUG, Guttorm R., CZOMPO, Joseph, LUO, Ning, JOHNSON, Kelly G.
• Application Number:
  US13/309,521
• Publication Number:
  US 20120173195A1
• Time in Patent Office: Days
• US Class Current: 702/151
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/393 Trajectory determination or predictive tracking, e.g. Kalman filtering
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

An apparatus and method for providing an improved heading estimate of a mobile device in a vehicle is presented. First, the mobile device determines if it is mounted in a cradle attached to the vehicle; if so, inertia sensor data may be valid. While in a mounted stated, the mobile device determines whether it has been rotated in the cradle; if so, inertia sensor data may no longer be reliable and a recalibration to determine a new relative orientation between the vehicle and the mobile device is needed. If the mobile device is mounted and not recently rotated, heading data from multiple sensors (e.g., GPS, gyroscope, accelerometer) may be computed and combined to form the improved heading estimate. This improved heading estimate may be used to form an improved velocity estimate. The improved heading estimate may also be used to compute a bias to correct a gyroscope.

Claims

1. A method in a mobile device for generating a gyroscope bias, the method comprising:

receiving at least two GNSS headings (H_GNSS) from a GNSS receiver;

computing an GNSS heading difference (Δ

H_GNSS) based on the GNSS headings (H_GNSS);

converting the GNSS heading difference (Δ

H_GNSS) to a negative GNSS heading rate (−

{dot over (H)}_GNSS) by scaling by a GNSS time difference (−

Δ

T_GNSS);

receiving gyroscope measurements ({right arrow over (ω

)}) from a gyroscope;

computing the virtual gyroscope heading rate ({dot over (H)}_Gyro,CORR) from the gyroscope measurements ({right arrow over (ω

)});

forming a corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) from the virtual gyroscope heading rate ({dot over (H)}_Gyro);

averaging the corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) to form the virtual gyroscope heading rate ({dot over ( H_Gyro,CORR), and

summing the negative GNSS heading rate (−

{dot over (H)}_GNSS) and the virtual gyroscope heading rate ({dot over ( H_Gyro) to form the gyroscope bias.

2. The method of claim 1, further comprising feeding back the gyroscope bias as a preliminary gyroscope correction.

3. The method of claim 1, wherein forming the corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) comprises summing the virtual gyroscope heading rate ({dot over (H)}_Gyro) and the gyroscope bias signal.

4. A mobile device to generate a gyroscope bias, the mobile device comprising:

an inertial measurement unit comprising an accelerometer and a gyroscope;

a Global Navigation Satellite Systems receiver (GNSS receiver);

a processor coupled to the inertial measurement unit and the GNSS receiver; and

memory coupled to the processor, comprising code for;

receiving at least two GNSS headings (H_GNSS) from the GNSS receiver;

computing an GNSS heading difference (Δ

H_GNSS) based on the GNSS headings (H_GNSS);

converting the GNSS heading difference (Δ

H_GNSS) to a negative GNSS heading rate (−

{dot over (H)}_GNSS) by scaling by a GNSS time difference (−

Δ

T_GNSS);

receiving gyroscope measurements ({right arrow over (ω

)}) from the gyroscope;

computing the virtual gyroscope heading rate ({dot over (H)}_Gyro) from the gyroscope measurements ({right arrow over (ω

)});

forming a corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) from the virtual gyroscope heading rate ({dot over (H)}_Gyro);

averaging the corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) to form the virtual gyroscope heading rate ({dot over ( H_Gyro,CORR), and

summing the negative GNSS heading rate (−

{dot over (H)}_GNSS) and the virtual gyroscope heading rate ({dot over ( H_Gyro) to form the gyroscope bias.

5. A mobile device to generate a gyroscope bias, the mobile device comprising:

means for receiving at least two GNSS headings (H_GNSS) from a GNSS receiver;

means for computing an GNSS heading difference (Δ

H_GNSS) based on the GNSS headings (H_GNSS);

means for converting the GNSS heading difference (Δ

H_GNSS) to a negative GNSS heading rate (−

{dot over (H)}_GNSS) by scaling by a GNSS time difference (−

Δ

T_GNSS);

means for receiving gyroscope measurements ({right arrow over (ω

)}) from a gyroscope;

means for computing the virtual gyroscope heading rate ({dot over (H)}_Gyro) from the gyroscope measurements ({right arrow over (ω

)});

means for forming a corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) from the virtual gyroscope heading rate ({dot over (H)}_Gyro);

means for averaging the corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) to form the virtual gyroscope heading rate ({dot over ( H_Gyro,CORR), and

means for summing the negative GNSS heading rate (−

{dot over (H)}_GNSS) and the virtual gyroscope heading rate ({dot over ( H_Gyro) to form the gyroscope bias.

6. A device comprising a processor and a memory wherein the memory includes software instructions for:

receiving at least two GNSS headings (H_GNSS) from a GNSS receiver;

computing an GNSS heading difference (Δ

H_GNSS) based on the GNSS headings (H_GNSS);

converting the GNSS heading difference (Δ

H_GNSS) to a negative GNSS heading rate (−

{dot over (H)}_GNSS) by scaling by a GNSS time difference (−

Δ

T_GNSS);

receiving gyroscope measurements ({right arrow over (ω

)}) from a gyroscope;

computing the virtual gyroscope heading rate ({dot over (H)}_Gyro) from the gyroscope measurements ({right arrow over (ω

)});

forming a corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) from the virtual gyroscope heading rate ({dot over (H)}_Gyro);

averaging the corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) to form the virtual gyroscope heading rate ({dot over ( H_Gyro,CORR), and

summing the negative GNSS heading rate (−

{dot over (H)}_GNSS) and the virtual gyroscope heading rate ({dot over ( H_Gyro) to form the gyroscope bias.

7. A non-volatile computer-readable storage medium including program code stored thereon, comprising program code for:

receiving at least two GNSS headings (H_GNSS) from a GNSS receiver;

computing an GNSS heading difference (Δ

H_GNSS) based on the GNSS headings (H_GNSS);

converting the GNSS heading difference (Δ

H_GNSS) to a negative GNSS heading rate (−

{dot over (H)}_GNSS) by scaling by a GNSS time difference (−

Δ

T_GNSS);

receiving gyroscope measurements ({right arrow over (ω

)}) from a gyroscope;

computing the virtual gyroscope heading rate ({dot over (H)}_Gyro) from the gyroscope measurements ({right arrow over (ω

)});

forming a corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) from the virtual gyroscope heading rate ({dot over (H)}_Gyro);

averaging the corrected gyroscope heading rate ({dot over (H)}_Gyro,CORR) to form the virtual gyroscope heading rate ({dot over ( H_Gyro,CORR), and

summing the negative GNSS heading rate (−

{dot over (H)}_GNSS) and the virtual gyroscope heading rate ({dot over ( H_Gyro) to form the gyroscope bias.

8. A method in a mobile device for generating a gyroscope bias, the method comprising:

receiving a GNSS heading (H_GNSS),

receiving gyroscope measurements ({right arrow over (ω

)}); and

computing the gyroscope bias based on the GNSS heading (H_GNSS) and the gyroscope measurements ({right arrow over (ω

)}).

9. The method of claim 8, wherein computing the gyroscope bias comprise

10. A mobile device to generate a gyroscope bias, the mobile device comprising:

an inertial measurement unit comprising an accelerometer and a gyroscope;

a Global Navigation Satellite Systems receiver (GNSS receiver);

a processor coupled to the inertial measurement unit and the GNSS receiver; and

memory coupled to the processor, comprising code for;

receiving a GNSS heading (H_GNSS),

receiving gyroscope measurements ({right arrow over (ω

)}); and

computing the gyroscope bias based on the GNSS heading (H_GNSS) and the gyroscope measurements ({right arrow over (ω

)}).

11. A mobile device to generate a gyroscope bias, the mobile device comprising:

means for receiving a GNSS heading (H_GNSS);

means for receiving gyroscope measurements ({right arrow over (ω

)}); and

means for computing the gyroscope bias based on the GNSS heading (H_GNSS) and the gyroscope measurements ({right arrow over (ω

)}).

12. A device comprising a processor and a memory wherein the memory includes software instructions for:

receiving a GNSS heading (H_GNSS);

receiving gyroscope measurements ({right arrow over (ω

)}); and

computing a gyroscope bias based on the GNSS heading (H_GNSS) and the gyroscope measurements ({right arrow over (ω

)}).

13. A non-volatile computer-readable storage medium including program code stored thereon, comprising program code for:

receiving a GNSS heading (H_GNSS);

receiving gyroscope measurements ({right arrow over (ω

)}); and

computing a gyroscope bias based on the GNSS heading (H_GNSS) and the gyroscope measurements ({right arrow over (ω

)}).