Drawbar position determination with rotational sensors

Patent metadata

Field	Value
Publication number	US-10030366-B2
Application number	US-201615090191-A
Country	US
Kind code	B2
Filing date	Apr 4, 2016
Priority date	Apr 4, 2016
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

In a motor grader, a total drawbar position may be determined based on signals from various sensors on a drawbar-circle-moldboard (DCM) assembly. The sensors can include rotational sensors for one or both lift arm angles, and one or both yoke primary angles in combination with sensors detecting lengths of the lift cylinders. The sensor information may be used to calculate roll, pitch and yaw angles of the drawbar relative to a frame of the motor grader.

First claim

What is claimed is:

1. A motor grader comprising:
a frame;
a drawbar that is multi-dimensional rotationally connected to the frame;
a left lift arm pivotally connected to the frame;
a right lift arm pivotally connected to the frame;
a link bar pivotally connected to the left lift arm and the right lift arm;
a left yoke pivotally connected to the left lift arm for rotation relative to the left lift arm about a left yoke primary axis;
a left lift cylinder pivotally connected to the left yoke for rotation relative to the left yoke about a left yoke secondary axis, and multi-dimensional rotationally connected to the drawbar;
a right yoke pivotally connected to the right lift arm for rotation relative to the right lift arm about a right yoke primary axis;
a right lift cylinder pivotally connected to the right yoke for rotation relative to the right yoke about a right yoke secondary axis, and multi-dimensional rotationally connected to the drawbar;
a side shift cylinder multi-dimensional rotationally connected to the link bar by a first side shift cylinder connection and multi-dimensional rotationally connected to the drawbar by a second side shift cylinder connection;
a left lift arm angle sensor operatively associated with the left lift arm to sense a left lift arm angle relative to the frame and output a left lift arm angle sensor signal that corresponds to the left lift arm angle;
a left yoke primary angle sensor operatively associated with the left yoke to sense a left yoke primary angle relative to the left lift arm and output a left yoke primary angle sensor signal that corresponds to the left yoke primary angle;
a left lift cylinder length sensor operatively associated with the left lift cylinder to sense a left lift cylinder length of the left lift cylinder and output a left lift cylinder length sensor signal that corresponds to the left lift cylinder length;
a right lift cylinder length sensor operatively associated with the right lift cylinder to sense a right lift cylinder length of the right lift cylinder and output a right lift cylinder length sensor signal that corresponds to the right lift cylinder length; and
a controller operatively connected to the left lift arm angle sensor, the left yoke primary angle sensor, the left lift cylinder length sensor and the right lift cylinder length sensor, the controller being configured to calculate drawbar orientation angles of the drawbar relative to the frame based on the left lift arm angle sensor signal, the left yoke primary angle sensor signal, the left lift cylinder length sensor signal and the right lift cylinder length sensor signal.

2. The motor grader of claim 1 , wherein the controller being configured to calculate the drawbar orientation angles comprises configuring the controller to:
calculate a left lift cylinder multi-dimensional rotation connection location relative to the frame;
calculate a right lift cylinder multi-dimensional rotation connection location relative to the frame; and
calculate a drawbar roll angle, a drawbar yaw angle and a drawbar pitch angle with respect to the frame based on the left lift cylinder multi-dimensional rotation connection location and the right lift cylinder multi-dimensional rotation connection location.

3. The motor grader of claim 2 , wherein the link bar has a plurality of link bar holes extending there through, and wherein the motor grader comprises a center pin operatively connected to the frame and selectively extendable for insertion into one of the plurality of link bar holes disposed proximate the center pin to fix the left lift arm, the right lift arm and the link bar relative to the frame.

4. The motor grader of claim 3 , wherein the controller is configured to determine the one of the plurality of link bar holes in which the center pin is inserted based on the left lift arm angle of the left lift arm angle sensor signal, and to determine a first side shift cylinder multi-dimensional rotation connection location based on the one of the plurality of link bar holes in which the center pin is inserted.

5. The motor grader of claim 2 , wherein the controller is configured to:
determine a first side shift cylinder multi-dimensional rotation connection location based on the left lift arm angle of the left lift arm angle sensor signal;
determine a second side shift cylinder multi-dimensional rotation connection location based on the left lift cylinder multi-dimensional rotation connection location and the right lift cylinder multi-dimensional rotation connection location; and
calculate a side shift cylinder length as a distance between the first side shift cylinder multi-dimensional rotation connection location and the second side shift cylinder multi-dimensional rotation connection location.

6. The motor grader of claim 5 , wherein the controller is configured to calculate the second side shift cylinder multi-dimensional rotation connection location relative to the frame based on the left lift cylinder multi-dimensional rotation connection location, the right lift cylinder multi-dimensional rotation connection location, and a known relative position of the second side shift cylinder multi-dimensional rotation connection location on the drawbar with respect to a left lift cylinder multi-dimensional rotation connection and a right lift cylinder multi-dimensional rotation connection.

7. The motor grader of claim 2 , wherein the controller is configured to:
calculate the left lift cylinder multi-dimensional rotation connection location relative to the frame based on the left lift arm angle of the left lift arm angle sensor signal, the left yoke primary angle of the left yoke primary angle sensor signal and the left lift cylinder length of the left lift cylinder length sensor signal; and
calculate the right lift cylinder multi-dimensional rotation connection location relative to the frame based on the left lift cylinder multi-dimensional rotation connection location, a right lift arm angle and the right lift cylinder length of the right lift cylinder length sensor signal.

8. The motor grader of claim 7 , wherein the controller is configured to:
calculate a left yoke absolute primary angle relative to the frame by adding the left lift arm angle to the left yoke primary angle; and
calculate the left lift cylinder multi-dimensional rotation connection location relative to the frame based on the left yoke absolute primary angle and the left lift cylinder length of the left lift cylinder length sensor signal.

9. The motor grader of claim 2 , wherein the controller is configured to calculate a side shift cylinder length from the first side shift cylinder connection to the second side shift cylinder connection based on the left lift arm angle sensor signal, the left yoke primary angle sensor signal, the left lift cylinder length sensor signal and the right lift cylinder length sensor signal.

10. A method for determining drawbar orientation angles of a drawbar of a motor grader that is multi-dimensional rotationally connected to a frame of the motor grader, wherein a link bar of the motor grader is connected to the frame by a left lift arm pivotally connected to the frame and to the link bar and a right lift arm pivotally connected to the frame and to the link bar, and the drawbar is suspended from the frame by a left lift cylinder and a right lift cylinder, wherein the left lift cylinder is multi-dimensional rotationally connected to the drawbar and pivotally connected to a left yoke that is pivotally connected to the left lift arm, and the right lift cylinder is multi-dimensional rotationally connected to the drawbar and pivotally connected to a right yoke that is pivotally connected to the right lift ar

Assignees

• Caterpillar Inc

Inventors

• Tevis Ethan M
• Kirsch Karl
• Gentle Michael C

Classifications

• E02F3/844

  for positioning the blade, e.g. hydraulically · CPC title

• E02F3/7654

  with the scraper blade being horizontally movable into a position near the chassis · CPC title

• E02F3/765

  with the scraper blade being pivotable about a horizontal axis disposed perpendicular to the blade · CPC title

• E02F3/7645

  with the scraper blade being pivotable about a horizontal axis disposed parallel to the blade · CPC title

• E02F3/764

  with the scraper blade being pivotable about a vertical axis · CPC title