MOTION-BASED ADAPTIVE FREQUENCY ESTIMATION OF A DOPPLER VELOCITY SENSOR

• US 20120326918A1
• Filed: 06/21/2011
• Published: 12/27/2012
• Est. Priority Date: 06/21/2011
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Ingvalson, Ryan, McCroskey, Robert C., Hawkinson, Wesley J.
• Granted Patent: US 8,917,203 B2
• Time in Patent Office: Days
• US Class Current: 342/104
• CPC Class Codes: G01C 21/10 by using measurements of speed or acceleration G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01S 13/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track G01S13/64 takes precedence
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder

Abstract

A system and method for motion-based adaptive frequency estimation of a Doppler sensor is provided. The system comprises a Doppler sensor configured to output a digitized Doppler data signal, and a Doppler velocity estimation module operatively coupled to the Doppler sensor to receive the Doppler data signal. An inertial navigation system is operatively coupled to the Doppler velocity estimation module, and one or more inertial sensors is operatively coupled to the inertial navigation system. The inertial sensors are configured to transmit inertial navigation data to the inertial navigation system. The Doppler velocity estimation module calculates a speed or velocity estimate based on the Doppler data signal and the inertial navigation data. The speed or velocity estimate is then transmitted to the inertial navigation system.

Claims

1. A system for motion-based adaptive frequency estimation of a Doppler sensor, the system comprising:

a Doppler sensor configured to output a digitized Doppler data signal;

a Doppler velocity estimation module operatively coupled to the Doppler sensor to receive the Doppler data signal;

an inertial navigation system operatively coupled to the Doppler velocity estimation module; and

one or more inertial sensors operatively coupled to the inertial navigation system and configured to transmit inertial navigation data to the inertial navigation system;

wherein the Doppler velocity estimation module calculates a speed or velocity estimate based on the Doppler data signal and the inertial navigation data;

wherein the speed or velocity estimate is transmitted to the inertial navigation system.

2. The system of claim 1, wherein the Doppler velocity estimation module further calculates an error estimate for the speed or velocity estimate, and the error estimate is transmitted to the inertial navigation system.

3. The system of claim 1, wherein the Doppler data signal includes in-phase or quadrature-phase data.

4. The system of claim 1, wherein the inertial sensors are implemented in an inertial measurement unit.

5. The system of claim 1, wherein the Doppler velocity estimation module comprises a frequency estimation algorithm configured to receive the Doppler data signal, and a parameter selection block configured to transmit frequency estimation parameters to the frequency estimation algorithm

6. The system of claim 5, wherein the frequency estimation algorithm is configured to compute an estimated frequency based on the Doppler data signal and the frequency estimation parameters.

7. The system of claim 5, wherein the frequency estimation parameters include number of data points and length of zero-padding.

8. The system of claim 5, wherein the Doppler velocity estimation module further comprises a speed/velocity estimation block configured to calculate an average speed based on frequency data, or an average velocity based on frequency data and direction data.

9. The system of claim 5, wherein the Doppler velocity estimation module further comprises an error estimation block configured to calculate total error in average speed or average velocity.

10. The system of claim 4, wherein the Doppler velocity estimation module further comprises a data segment selection block operatively coupled to the parameter selection block.

11. A method for motion-based adaptive frequency estimation of a Doppler sensor, the method comprising:

receiving a digitized Doppler data signal from the Doppler sensor;

determining Doppler frequency estimation parameters based on inertial navigation data;

calculating a Doppler frequency estimate based on the Doppler data signal and the frequency estimation parameters; and

calculating an average speed or velocity estimate based on the Doppler frequency estimate.

12. The method of claim 11, further comprising calculating an error estimate for the Doppler frequency estimate.

13. The method of claim 11, wherein the digitized Doppler data signal includes in-phase or quadrature-phase data.

14. The method of claim 11, wherein the digitized Doppler data includes in-phase and quadrature-phase data.

15. The method of claim 11, wherein the frequency estimation parameters include number of data points and length of zero-padding.

16. The method of claim 11, wherein the average speed is estimated by using a scaling factor to convert the estimated frequency to the average speed estimate.

17. The method of claim 11, wherein the average velocity is estimated by using a scaling factor to convert the estimated frequency to the average speed estimate, and determining a sign of the average speed estimate based on a direction indicator.

18. A computer program product, comprising:

a computer readable medium having instructions stored thereon executable by a processor to perform a method for motion-based adaptive frequency estimation of a Doppler sensor according to the method of claim 11.

20. A computer program product, comprising:

a computer readable medium having instructions stored thereon executable by a processor to perform a method for motion-based adaptive frequency estimation of a Doppler sensor according to the method of claim 17.

19. A method for motion-based adaptive frequency estimation of a Doppler sensor, the method comprising:

(a) obtaining velocity and acceleration data;

(b) determining whether the velocity and acceleration data is valid;

(c) when the velocity and acceleration data is valid, selecting a data time region;

(d) determining Doppler frequency estimation parameters based on the velocity and acceleration data;

(e) determining whether the frequency estimation parameters are valid;

(f) if the frequency estimation parameters are not valid, determining whether iterations are required;

(g) if the iterations are required, returning to (c) to select another data time region and repeating (d) and (e);

(h) if the frequency estimation parameters are valid, obtaining digitized Doppler data;

(i) determining whether the Doppler data is valid;

(j) if the Doppler data is valid, calculating a Doppler frequency estimate based on the Doppler data and the frequency estimation parameters;

(k) determining whether the Doppler frequency estimate is valid; and

(l) if the Doppler frequency estimate is valid, calculating an average speed or velocity estimate based on the Doppler frequency estimate.