Position aided inertial navigation system for a farming implement not requiring an additional GNSS receiver

Patent metadata

Field	Value
Publication number	US-10123472-B1
Application number	US-201615200995-A
Country	US
Kind code	B1
Filing date	Jul 1, 2016
Priority date	Jul 1, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

Systems, apparatus, and methods for informing an on-tractor navigation system of position of a towed implement. In one aspect, a non-GNSS sensor mounted on the implement provides heading information to the navigation system. Knowledge of the geometry of the implement along with navigation coordinate frame position information from the navigation system, allows a relatively economical and flexible way to derive implement position information without the expense of a GNSS receiver on the implement Adding inertial sensors on the implement can allow position determination of any point on the implement relative to the ground. This can be advantageously used for swath and rate control for implements.

First claim

The invention claimed is:

1. A method of autosteering a tractor with a precision agriculture navigation system on-board and towing from a hitch point an implement without a GNSS antenna or receiver on-board comprising:
a. obtaining heading information related to heading of the implement without a GNSS antenna or receiver;
b. obtaining hitch point position information from the tractor navigation system;
c. obtaining inertial information related to at least one of roll rate and pitch rate of the implement from inertial sensors mounted at mounting locations on the implement, including locations where effectiveness of a GNSS antenna would not be reliable;
d. using hitch point position information and inertial information from the inertia sensors mounted on the implement to estimate at least one of roll angle and pitch angle of the implement; and
e. using the heading information from the inertia sensors mounted on the implement, inertial information, and the hitch point position information to provide autosteering instructions to the tractor to keep the implement on a predetermined path computed by the navigation system.

2. The method of claim 1 wherein the heading information is obtained from:
a. a magnetometer on the implement.

3. The method of claim 1 wherein the inertial information comprises accelerations and angular rates.

4. The method of claim 3 wherein the accelerations and angular rates are communicated to the navigation system and used to estimate roll and pitch of the implement.

5. The method of claim 4 further comprising using the roll and pitch estimates by the navigation system when generating swath or rate instructions related to the implement.

6. The method of claim 3 wherein the inertial information is from an IMU which includes the inertia sensors on the implement.

7. The method of claim 1 wherein the implement is a planter.

8. The method of claim 1 wherein the implement is an applicator of gas, liquid, or solid phase substances.

9. The method of claim 1 wherein:
a. the heading information is obtained from a magnetometer on the implement; and
b. the inertial information is obtained from the inertial sensors comprising at least three accelerometers on the implement.

10. The method of claim 1 wherein the navigation system comprises GNSS aided INS and hitch position is derived from the navigation system.

11. A system including a tractor with an on-board navigation system and towing from a hitch point an implement without a GNSS antenna or receiver on-board the implement comprising:
a. a navigation system on the tractor for obtaining hitch point position information;
b. at least one inertial sensor mounted at a mounting location on the implement, including locations where effectiveness of a GPS antenna would not be reliable, for obtaining and communicating heading information of the implement to the tractor navigation system;
c. the at least one inertial sensor on the implement communicating with the tractor navigation system for obtaining, in combination with the hitch point position information, at least one of implement roll and pitch angle estimates;
d. so that heading information and pitch and roll angle information related to the implement from the inertial sensor on the implement is available for deriving position information of the implement in navigation coordinate frame without a GNSS antenna or receiver on the implement.

12. The system of claim 11 wherein the at least one inertial sensor from which heading information can be derived comprises;
a. a magnetometer on the implement.

13. The system of claim 12 wherein the at least one inertial sensor comprise an IMU.

14. The system of claim 11 further comprising an auto-steering system associated with the vehicle and the position information of the implement is used to generate auto-steering instructions from the navigation system.

15. The system of claim 11 wherein the at least one inertial sensor mounted on the implement comprise at least three accelerometers.

16. The system of claim 11 wherein the roll and pitch angle estimates are included by the navigation system in generating swath or rate instructions to the implement.

17. The system of claim 16 wherein the implement comprises a planter.

18. The system of claim 16 wherein the implement comprises an applicator of gas, liquid or solid phase substance.

19. The system of claim 11 wherein the vehicle comprises a tractor for use in an agricultural field.

20. The system of claim 11 wherein the navigation system comprises a GNSS aided INS and hitch point position is derived from the navigation system.

21. A method of controlling a tractor towing at a hitch point an implement in a field comprising:
a. providing a tractor with a navigation system and autosteering system on-board;
b. providing an implement with a plurality of inertial sensors on-board;
c. calculating with the navigation system a predetermined path for the implement through the field;
d. deriving hitch point position with the tractor navigation system;
e. deriving implement position in navigation coordinates using hitch point position from the tractor navigation system, implement heading from at least one of the plurality of inertia sensors on the implement and without a GNSS antenna or receiver, and three-axis accelerations from the inertial sensors on the implement; and
f. instructing the autosteering system using the derived implement position.

22. The method of claim 21 further comprising:
a. instructing at least one of swath or rate control using the derived implement position.

23. The method of claim 21 wherein the inertial sensors are associated with an IMU.

24. The method of claim 21 wherein the inertial sensors are in shared housing and include a magnetometer.

Assignees

• Ag Leader Tech
• Ag Leader Tech Inc

Inventors

• Schneider Michael

Classifications

• G01C21/165

  combined with non-inertial navigation instruments · CPC title

• A01B69/004 Primary

  automatic · CPC title

• G01C21/08

  involving use of the magnetic field of the earth · CPC title

• B62D15/025

  Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation (B62D1/28 takes precedence) · CPC title

• G01C21/1654

  with electromagnetic compass · CPC title