INCLINATION ANGLE COMPENSATION SYSTEMS AND METHODS

• US 20130080112A1
• Filed: 09/28/2011
• Published: 03/28/2013
• Est. Priority Date: 09/28/2011
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: FRIEND, Paul Russell
• Granted Patent: US 9,020,776 B2
• Time in Patent Office: Days
• US Class Current: 702/154
• CPC Class Codes: E02F 3/845 using mechanical sensors to determine the blade position, e.g. inclinometers, gyroscopes, pendulums
• CPC Class Codes: G01C 9/08 Means for compensating acceleration forces due to movement of instrument
• CPC Class Codes: G05D 1/0891 specially adapted for land vehicles

Abstract

An inclination angle compensation system for determining an inclination angle of a machine is disclosed. The inclination angle compensation system may have a non-gravitational acceleration estimator configured to estimate a non-gravitational acceleration of a machine based on an estimated inclination angle and an acceleration output from a forward acceleration sensor. The inclination angle compensation system may also have an inclination angle sensor corrector configured to receive an inclination angle output from an inclination angle sensor, determine an inclination angle sensor acceleration based on the inclination angle output, and calculate a corrected inclination angle of the machine based on the non-gravitational acceleration and the inclination angle sensor acceleration.

Claims

1. A computer-implemented method of determining an inclination of a machine comprising:

estimating a non-gravitational acceleration of a machine based on an estimated inclination angle and an acceleration output from a forward acceleration sensor;

receiving an inclination angle output from an inclination angle sensor;

determining an inclination angle sensor acceleration based on the inclination angle output; and

calculating a corrected inclination angle of the machine based on the non-gravitational acceleration and the inclination angle sensor acceleration.

2. The computer-implemented method according to claim 1, wherein the corrected inclination angle of the machine is calculated as:

3. The computer-implemented method according to claim 1, wherein the non-gravitational acceleration of the machine is estimated as:

A_non-g=A−

{circumflex over (β

)}_A−

g sin {circumflex over (θ

)}⁻

,

where A is the acceleration output from the forward acceleration sensor, {circumflex over (β

)}_A is an acceleration bias estimate, g is a conventional acceleration due to gravity, and {circumflex over (θ

)}⁻

is the estimated inclination angle.

4. The computer-implemented method according to claim 1, wherein the inclination angle sensor acceleration is determined as:

A_i=g sin θ

,

where g is a conventional acceleration due to gravity and θ

is the inclination angle output.

5. The computer-implemented method according to claim 1, further including:

receiving an inclination angular rate from an inclination angular rate sensor; and

integrating the inclination angular rate to estimate the estimated inclination angle.

6. The computer-implemented method according to claim 5, wherein the estimated inclination angle is estimated using a predict phase of a Kalman filter.

7. The computer-implemented method according to claim 6, further including:

outputting the corrected inclination angle to an update phase of the Kalman filter; and

generating an a posteriori estimated inclination angle with the Kalman filter based on the corrected inclination angle and the estimated inclination angle from the predict phase of the Kalman filter.

8. An inclination angle compensation system for determining an inclination angle of a machine comprising:

a non-gravitational acceleration estimator configured to estimate a non-gravitational acceleration of a machine based on an estimated inclination angle and an acceleration output from a forward acceleration sensor; and

an inclination angle sensor corrector configured to;

receive an inclination angle output from an inclination angle sensor;

determine an inclination angle sensor acceleration based on the inclination angle output; and

calculate a corrected inclination angle of the machine based on the non-gravitational acceleration and the inclination angle sensor acceleration.

9. The system according to claim 8, wherein the inclination angle sensor corrector is further configured to calculate the corrected inclination angle of the machine as:

10. The system according to claim 8, wherein the non-gravitational acceleration estimator is further configured to estimate the non-gravitational acceleration of the machine as:

A_non-g=A−

{circumflex over (β

)}_A−

g sin {circumflex over (θ

)}⁻

,

where A is the acceleration output from the forward acceleration sensor, {circumflex over (β

)}_A is an acceleration bias estimate, g is a conventional acceleration due to gravity, and {circumflex over (θ

)}⁻

is the estimated inclination angle.

11. The system according to claim 8, wherein the inclination angle sensor corrector is further configured to determine the inclination angle sensor acceleration as:

A_i=g sin θ

,

where g is a conventional acceleration due to gravity and θ

is the inclination angle output.

12. The system according to claim 8, further including:

an inclination angle estimator configured to;

receive an inclination angular rate from an inclination angular rate sensor;

integrate the inclination angular rate to estimate the estimated inclination angle; and

output the estimated inclination angle to the non-gravitational acceleration estimator.

13. The system according to claim 12, wherein the inclination angle estimator is further configured to estimate the estimated inclination angle by implementing a predict phase of a Kalman filter.

14. The system according to claim 13, further including an inclination angle updater, wherein:

the inclination angle sensor corrector is further configured to output the corrected inclination angle to the inclination angle updater; and

the inclination angle updater is configured to generate an a posteriori estimated inclination angle by implementing an update phase of the Kalman filter based on the corrected inclination angle and the estimated inclination angle from the predict phase of the Kalman filter.

15. A computer-readable storage device storing instructions for determining an inclination of a machine, the instructions causing one or more computer processors to perform operations comprising:

estimating a non-gravitational acceleration of a machine based on an estimated inclination angle and an acceleration output from a forward acceleration sensor;

receiving an inclination angle output from an inclination angle sensor;

determining an inclination angle sensor acceleration based on the inclination angle output; and

calculating a corrected inclination angle of the machine based on the non-gravitational acceleration and the inclination angle sensor acceleration.

16. The computer-readable storage device according to claim 15, wherein the corrected inclination angle of the machine is calculated as:

17. The computer-readable storage device according to claim 15, wherein the non-gravitational acceleration of the machine is estimated as:

A_non-g=A−

{circumflex over (β

)}_A−

g sin {circumflex over (θ

)}⁻

,

where A is the acceleration output from the forward acceleration sensor, {circumflex over (β

)}_A is an acceleration bias estimate, g is a conventional acceleration due to gravity, and {circumflex over (θ

)}⁻

is the estimated inclination angle.

18. The computer-readable storage device according to claim 15, the instructions further causing the one or more computer processors to perform operations including:

receiving an inclination angular rate from an inclination angular rate sensor; and

integrating the inclination angular rate to estimate the estimated inclination angle.

19. The computer-readable storage device according to claim 18, wherein the estimated inclination angle is estimated using a predict phase of a Kalman filter.

20. The computer-readable storage device according to claim 19, the instructions further causing the one or more computer processors to perform operations including:

outputting the corrected inclination angle to an update phase of the Kalman filter; and

generating an a posteriori estimated inclination angle with the Kalman filter based on the corrected inclination angle and the estimated inclination angle from the predict phase of the Kalman filter.