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1. WO2020117563 - YAW ESTIMATION

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

WHAT IS CLAIMED IS:

1. A method for estimating yaw of a dozer blade coupled to a dozer by a c-frame, wherein the dozer blade is rotatable to change the yaw of the dozer blade relative to the c-frame, the method comprising:

receiving an estimated pitch and roll of the dozer blade;

receiving an estimated pitch and roll of the c-frame;

moving the c-frame to simultaneously rotate an inertial measurement unit (IMU) coupled to the dozer blade and an IMU coupled to the c-frame, wherein measurement axes of the IMU coupled to the dozer blade and measurement axes of the IMU coupled to the c-frame are approximately aligned;

receiving gyro signals of the IMU coupled to the dozer blade, wherein at least some of the gyro signals of the IMU coupled to the dozer blade include signals obtained while the c-frame is moving and the yaw of the dozer blade is substantially static;

receiving gyro signals of the IMU coupled to the c-frame, wherein at least some of the gyro signals of the IMU coupled to the c-frame include signals obtained while the c- frame is moving;

reducing effects of the estimated pitch and roll of the dozer blade on the gyro signals of the IMU coupled to the dozer blade to provide corrected dozer blade gyro signals;

reducing effects of the estimated pitch and roll of the c-frame on the gyro signals of the IMU coupled to the c-frame to provide corrected c-frame gyro signals; and

estimating the yaw of the dozer blade relative to the c-frame based on the corrected dozer blade gyro signals and the corrected c-frame gyro signals.

2. The method of claim 1 , wherein the pitch and roll of the dozer blade is estimated using the IMU coupled to the dozer blade, and the pitch and roll of the c-frame is estimated using the IMU coupled to the c-frame.

3. The method of claim 1 , wherein at least one of the pitch and roll of the dozer blade or the pitch and roll of the c-frame are estimated without using signals from an IMU.

4. The method of claim 1 , wherein the yaw of the dozer blade relative to the c-frame is estimated using Euler angles.

5. The method of claim 1 , further comprising:

rotating the dozer blade to change the yaw of the dozer blade;

receiving gyro signals of the IMU coupled to the dozer blade while the dozer blade is rotating; and

estimating the yaw of the dozer blade relative to the c-frame based on the gyro signals received while the dozer blade is rotating.

6. The method of claim 1 , wherein the gyro signals of the IMU coupled to the dozer blade and the gyro signals of the IMU coupled to the c-frame provide information on angular velocity of the dozer blade and angular velocity of the c-frame respectively in Cartesian reference frames.

7. The method of claim 1 , wherein the measurement axes of the IMU coupled to the dozer blade and the measurement axes of the IMU coupled to the c-frame each include an axis associated with pitch and an axis associated with roll, and wherein the gyro signals of the IMU coupled to the dozer blade and the gyro signals of the IMU coupled to the c-frame provide information on angular velocity associated with the pitch and angular velocity associated with the roll.

8. The method of claim 1 , wherein the measurement axes of the IMU coupled to the dozer blade and the measurement axes of the IMU coupled to the c-frame each include an axis associated with pitch, an axis associated with roll, and an axis associated with yaw, and wherein the yaw of the dozer blade relative to the c-frame is estimated using gyro signals associated with the pitch and gyro signals associated with the roll without using gyro signals associated with the yaw.

9. The method of claim 1 , wherein the effects of the estimated pitch and roll of the dozer blade are reduced by mapping the gyro signals of the IMU coupled to the dozer blade to an approximately level plane.

10. A system for estimating yaw of an implement coupled to a machine, wherein the implement is rotatable to change the yaw of the implement relative to the machine, the system comprising:

a first gyro sensor coupled to the implement;

a second gyro sensor coupled to the machine, wherein the machine is configured so that movement of at least a portion of the machine simultaneously changes at least one of a pitch of the first gyro sensor and a pitch of the second gyro sensor or a roll of the first gyro sensor and a roll of the second gyro sensor; and

a computer system communicatively coupled to the first gyro sensor and to the second gyro sensor, the computer system configured to:

receive gyro signals of the first gyro sensor, wherein at least some of the gyro signals of the first gyro sensor include signals obtained while at least the portion of the machine is moving and the yaw of the implement is substantially static;

receive gyro signals of the second gyro sensor, wherein at least some of the gyro signals of the second gyro sensor include signals obtained while at least the portion of the machine is moving; and

estimate the yaw of the implement relative to the machine based on the gyro signals of the first gyro sensor and the gyro signals of the second gyro sensor.

11. The system of claim 10 wherein the computer system is further configured to:

reduce effects of an estimated pitch and roll of the implement on the gyro signals of the first gyro sensor to provide first corrected gyro signals; and

reduce effects of an estimated pitch and roll of the machine on the gyro signals of the second gyro sensor to provide second corrected gyro signals, wherein the gyro signals of the first gyro sensor used to estimate the yaw of the implement relative to the machine are the first corrected gyro signals, and the gyro signals of the second gyro sensor used to estimate the yaw of the implement relative to the machine are the second corrected gyro signals.

12. The system of claim 10, wherein the implement is a dozer blade and the machine is a dozer that includes a c-frame coupled to the dozer blade, and wherein the second gyro sensor is coupled to the c-frame.

13. The system of claim 10, wherein measurement axes of the first gyro sensor and measurement axes of the second gyro sensor are approximately aligned.

14. The system of claim 10, wherein the first gyro sensor is coupled to the implement at a known orientation relative to the second gyro sensor coupled to the machine.

15. A method for estimating yaw of first gyro sensors relative to second gyro sensors, wherein the first gyro sensors and the second gyro sensors are mounted on separate bodies having a semi-rigid coupling so that a change in pitch or roll of the second gyro sensors results in a corresponding change in pitch or roll of the first gyro sensors, and the first gyro sensors are rotatable to change the yaw of the first gyro sensors relative to the second gyro sensors, the method comprising:

moving the second gyro sensors to simultaneously change at least one of the pitch of the first gyro sensors and the pitch of the second gyro sensors or the roll of the first gyro sensors and the roll of the second gyro sensors;

receiving first gyro signals of the first gyro sensors, wherein at least some of the first gyro signals include signals obtained while the first gyro sensors and the second gyro sensors are moving and the yaw of the first gyro sensors is substantially static;

receiving second gyro signals of the second gyro sensors, wherein at least some of the second gyro signals include signals obtained while the first gyro sensors and the second gyro sensors are moving; and

estimating the yaw of the first gyro sensors relative to the second gyro sensors based on the first gyro signals and the second gyro signals.

16. The method of claim 15, wherein measurement axes of the first gyro sensors and measurement axes of the second gyro sensors are approximately aligned.

17. The method of claim 15, further comprising:

receiving an estimated pitch and roll of the first gyro sensors;

receiving an estimated pitch and roll of the second gyro sensors;

reducing effects of the estimated pitch and roll of the first gyro sensors on the first gyro signals to provide first corrected gyro signals; and

reducing effects of the estimated pitch and roll of the second gyro sensors on the second gyro signals to provide second corrected gyro signals, wherein the first gyro signals used to estimate the yaw are the first corrected gyro signals, and the second gyro signals used to estimate the yaw are the second corrected gyro signals.

18. The method of claim 17, wherein the pitch and roll of the first gyro sensors are estimated using a first inertial measurement unit (1MU), and the pitch and roll of the second gyro sensors are estimated using a second 1MU.

19. The method of claim 17, wherein at least one of the pitch and roll of the first gyro sensors or the pitch and roll of the second gyro sensors are estimated without using signals from an 1MU.

20. The method of claim 15, wherein the first gyro sensors are mounted to an implement and the second gyro sensors are mounted on a machine.