Excavating earth from a dig site using an excavation vehicle

Patent metadata

Field	Value
Publication number	US-10801177-B2
Application number	US-201815877217-A
Country	US
Kind code	B2
Filing date	Jan 22, 2018
Priority date	Jan 23, 2017
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

This description provides an autonomous or semi-autonomous excavation vehicle that is capable of navigating through a dig site and carrying out an excavation routine using a system of sensors physically mounted to the excavation vehicle. The sensors collects any one or more of spatial, imaging, measurement, and location data representing the status of the excavation vehicle and its surrounding environment. Based on the collected data, the excavation vehicle executes instructions to carry out an excavation routine. The excavation vehicle is also able to carry out numerous other tasks, such as checking the volume of excavated earth in an excavation tool, and helping prepare a digital terrain model of the site as part of a process for creating the excavation routine.

First claim

What is claimed is:

1. A method for removing a volume of earth from a site, the method comprising:
accessing, from a computer memory coupled to an excavation vehicle (EV), a plurality of target tool paths, each tool path comprising a set of coordinates within a coordinate space of the site representing a portion of the volume of earth to be removed; and
executing, with a computer coupled to the EV, a set of instructions configured to cause the EV to perform steps comprising:
positioning a leading edge of a tool of the EV at a depth below a ground surface of the site;
moving the tool over a first distance along a target tool path of the accessed plurality;
measuring a fill level of the tool; and
responsive to determining that the fill level is below a threshold, moving the tool a second distance along the target tool path.

2. The method of claim 1 , wherein, when executed, the set of instructions further cause the EV to:
lower the leading edge of the tool to the depth; and
move the tool through the earth to excavate the earth.

3. The method of claim 2 , wherein moving the tool through the earth comprises maintaining the leading edge of the tool at the depth below the ground surface over the first distance.

4. The method of claim 2 , wherein moving the tool through the earth comprises dynamically adjusting a rate of excavation by adjusting at least one of an angle of the tool beneath the ground surface and a speed of the tool.

5. The method of claim 1 , further comprising:
recording, with a sensor mounted to the EV, a movement of the tool over an actual tool path in response to moving the tool along the target tool path, the actual tool path having a set of coordinates that differs from the set of coordinate of the target tool path.

6. The method of claim 5 , further comprising:
generating, with the computer, a comparison between the set of coordinates of the actual tool path and the set of coordinates of the target tool path; and
responsive to the comparison indicating a threshold difference between the sets of coordinates, executing the set of instructions to repeat the movement of the tool along the target tool path.

7. The method of claim 5 , further comprising:
generating, with the computer, a comparison between the set of coordinates of the actual tool path and the set of coordinates of the target tool path; and
responsive to the comparison indicating a threshold difference between the sets of coordinates, raising the tool above the ground surface.

8. The method of claim 1 , wherein while the tool is moved along the distance, the set of instructions further cause the EV to perform the steps comprising:
estimating a volume of earth excavated by the tool without interrupting the movement of the tool along the distance.

9. The method of claim 8 , wherein estimating the volume of earth excavated by the tool comprises:
integrating the depth of the leading edge over a distance traversed by the tool and a width of the tool.

10. The method of claim 8 , wherein estimating the volume of earth excavated by the tool comprises:
determining a pre-excavation volume of earth in a hole;
accessing a swell factor relating the volume of earth excavated by the tool to the pre-excavation volume of earth in the hole; and
estimating the volume of earth excavated by the tool using the swell factor and the pre-excavation volume of earth.

11. The method of claim 8 , wherein estimating the volume of earth excavated by the tool comprises recording sensor data describing a quantity of earth in front of the leading edge of the tool.

12. The method of claim 1 , further comprising:
updating the fill level of the tool based on an actual tool path;
recording, with a sensor, a speed of at least one of the tool and a drive system of the EV; and
continuing to move the tool through the earth based on the updated tool fill level and the recorded speed.

13. The method of claim 1 , wherein the set of instructions further cause the EV to move the tool over a finish tool path, the set instructions causing the EV to perform the steps comprising:
excavating a smaller volume of earth from the site than excavated during previous target tool paths;
adjusting a non-leading edge of the tool; and
reducing a speed of a drive system of the EV.

14. The method of claim 13 , wherein excavating the smaller volume of earth from the site comprises:
adjusting an angle of the tool beneath the ground surface; or
adjusting the depth of the tool beneath the ground surface.

15. The method of claim 1 , wherein the set of instructions further cause the EV to add one or more cutbacks, the set of instructions causing the EV to perform the steps comprising:
scanning, by one or more sensors, for one or more human operators within a hole; and
responsive to detecting a human operator within the hole, halting the EV.

16. The method of claim 1 , further comprising:
responsive to measuring a threshold fill level of the tool, measuring an angle of the tool beneath the ground surface;
adjusting the angle of the tool beneath the ground surface towards a target breakout angle; and
raising the tool above the ground surface.

17. The method of claim 1 , further comprising:
measuring a quantity of earth accumulated in front of the leading edge of the tool; and
responsive to measuring the quantity of earth to be greater than a threshold quantity, raising the tool above the ground surface.

18. The method of claim 1 , further comprising:
measuring a force of earth beneath the ground surface on the tool; and
responsive to measuring the force of earth to be greater than a threshold force, adjusting an angle of the tool beneath the ground surface.

19. The method of claim 1 , wherein positioning the leading edge of the tool at the depth below the ground surface comprises:
tracking a relative position of the leading edge of the tool within a virtual representation of the site.

20. The method of claim 19 , wherein tracking the relative position of the leading edge comprises measuring an absolute position using a global positioning system mounted to the tool.

21. The method of claim 19 , wherein tracking the relative position of the leading edge comprises measuring the relative position using an incline sensor mounted to the tool.

22. The method of claim 19 , wherein tracking the relative position of the leading edge comprises measuring the relative position with a linear encoder mounted to the EV.

23. The method of claim 19 , wherein tracking the relative position of the leading edge comprises measuring the relative position by measuring a pressure of a hydraulic system controlling the tool.

24. The method of claim 19 , wherein tracking the relative position of the leading edge comprises measuring the relative position with a spatial sensor mounted to the EV.

25. The method of claim 19 , wherein tracking the relative position of the leading edge comprises:
tracking, with global positioning sensors, an absolute position of a chassis of the EV within the coordinate space;
analyzing kinematic measurements describing the EV; and
determining a position of the tool relative to the chassis.

26. The method of claim 25 , wherein analysis of the kinematic measurements is performed using one or more of incline sensors, linear encoders, and rotary encoders.

27. The method of claim 1 , wherein positioning

Assignees

• Built Robotics Inc

Inventors

• Ready-Campbell Noah Austen
• Liang Andrew Xiao
• Chou Linus Page
• Walker Jr Edward Stephen
• Wawrzonek Christian John
• Ready-Campbell Cyrus Mcmann

Classifications

• G06V20/56

  exterior to a vehicle by using sensors mounted on the vehicle · CPC title

• G06T2207/30248

  Vehicle exterior or interior · CPC title

• G06T17/05

  Geographic models · CPC title

• G06T7/74

  involving reference images or patches · CPC title

• G01N33/24

  Earth materials (G01N33/42 takes precedence) · CPC title