Blended Position Solutions

• US 20150274157A1
• Filed: 03/26/2014
• Published: 10/01/2015
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Sharp, Alan
• Granted Patent: US 9,574,320 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E01C 19/004 Devices for guiding or controlling the machines along a predetermined path for graders or bulldozers E02F3/841; for other soil-shifting machines E02F9/2045
• CPC Class Codes: E02F 3/841 Devices for controlling and guiding the whole machine, e.g. by feeler elements and reference lines placed exteriorly of the machine construction of roads E01C19/008
• CPC Class Codes: G01C 15/06 Surveyors' staffs; Movable markers
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves

Abstract

Novel tools and techniques for determining a blended position solution for a vehicle, using data from multiple positioning devices, some of which can be external to the vehicle. Some techniques allow a control system of a vehicle to transition from receiving position data from one positioning device to receiving data from another device without ceasing operation and/or while limiting any resulting discontinuity the position solution (and any resulting work performed by the vehicle) to within acceptable tolerances.

Claims

1. A heavy equipment vehicle, comprising:

a computer system comprising a processor and a non-transitory computer readable medium having encoded thereon a set of instructions that are executable by the processor to perform one or more operations, the set of instructions comprising;

instructions to receive, from a first positioning device at a first location, first data indicating an estimated position of the heavy equipment vehicle at a first point in time;

instructions to receive, from a second positioning device oriented at a second location, second data indicating an estimated position of the heavy equipment vehicle at the first point in time;

instructions to determine a first weighting factor for the first data and a second weighting factor for the second data, wherein the first and second weighting factors specify a relative weight to be accorded to each of the first and second data at the first point in time;

instructions to apply the first weighting factor to the first data;

instructions to apply the second weighting factor to the second data;

instructions to determine a blended solution for a first position of the heavy equipment vehicle at the first point in time, based at least in part on the first and second data and the first and second weighting factors;

instructions to periodically determine the first and second weighting factors over time, wherein the first and second weighting factors vary over time, resulting in different weights being accorded the first data and second data over time; and

instructions to determine a plurality of blended solutions for the position of the vehicle over a period of time, the plurality of blended solutions describing a substantially continuous curve during a transition, over the period of time, from a state in which the second weighting factor disregards the second data in determining a blended solution for a position of the heavy equipment vehicle to a state in which the first weighting factor disregards the first data in determining a blended solution for a position of the heavy equipment vehicle;

instructions to control operation of the heavy equipment vehicle, based on the determined plurality of positions of the vehicle, to continuously operate the heavy equipment vehicle without pause during the transition.

2. The heavy equipment vehicle of claim 1, wherein the heavy equipment vehicle is a road grader.

3. The heavy equipment vehicle of claim 1, wherein the heavy equipment vehicle is a road paving machine.

4. The heavy equipment vehicle of claim 1, wherein the heavy equipment vehicle is a tractor.

5. A method, comprising:

orienting a first positioning device at a first location;

orienting a second positioning device at a second location;

generating, using the first positioning device, first data indicating an estimated position of a vehicle at a first point in time;

generating, using the second positioning device, second data indicating an estimated position of the vehicle at the first point in time;

receiving, at a computer, the first and second data;

determining, with the computer, a first weighting factor for the first data and a second weighting factor for the second data, wherein the first and second weighting factors specify a relative weight to be accorded to each of the first and second data at the first point in time;

applying, with the computer, the first weighting factor to the first data;

applying, with the computer, the second weighting factor to the second data;

determining, with the computer, a blended solution for a first position of the vehicle at the first point in time, based at least in part on the first and second data and the first and second weighting factors; and

controlling, with the computer, operation of the vehicle, based on the determined first position of the vehicle.

6. The method of claim 5, wherein the blended solution for the first position of the vehicle comprises an elevation of the vehicle.

7. The method of claim 5, wherein the blended solution for the first position of the vehicle comprises a cross-slope of the vehicle.

8. The method of claim 5, wherein controlling operation of the vehicle comprises comparing the determined first position with a terrain model.

9. The method of claim 5, wherein controlling operation of the vehicle comprises comparing the determined first position with a corridor model.

10. The method of claim 5, wherein the first and second positioning devices indicate an estimated position of a first target on the vehicle, and wherein the blended solution is a first blended solution for a first point of interest on the vehicle, the method further comprising:

generating, using a third positioning device, third data indicating an estimated position of a second target on the vehicle;

generating, using a fourth positioning device, fourth data indicating an estimated position of a second target on the vehicle;

receiving the third and fourth data with the computer; and

determining a second blended solution for a second point of interest on the vehicle.

11. The method of claim 10, further comprising:

calculating a first elevation of the first point of interest on the vehicle; and

calculating a second elevation of the second point of interest on the vehicle.

12. The method of claim 11, further comprising:

calculating a cross-slope of the vehicle based on the first and second elevations.

13. The method of claim 5, further comprising:

repositioning the first positioning device;

communicating, with the computer, a position of a target on the vehicle, based at least in part on position data received from the second positioning device.

14. The method of claim 13, further comprising:

identifying, with the first positioning device, the target on the vehicle, from among a plurality of targets on the vehicle, using an active target identifier that is unique to the target, to prevent the first positioning device from spuriously locking to another one of the plurality of targets.

15. The method of claim 5, further comprising:

receiving additional data from one or more additional positioning devices; and

determining a third weighting factor for the third data; and

applying the third weighting factor to the third data;

wherein determining a blended solution for the first position of the vehicle at the first point in time is based at least in part on the first, second, and third data, and the first, second, and third weighting factors.

16. The method of claim 5, further comprising:

reapplying, with the computer, the first and second weighting factors to the first and second data to determine a blended solution for a second position of the heavy equipment vehicle at a second point in time, wherein the first and second weighting factors change over time.

17. The method of claim 5, wherein at least one of the weighting factors varies according to one or more specified parameters.

18. The method of claim 17, wherein the one or more parameters comprise a distance from the first positioning device to the vehicle and a distance from the second positioning device to the vehicle.

19. The method of claim 17, wherein the one or more parameters comprise relative signal strengths of signals from the first and second positioning devices.

20. The method of claim 17, wherein the at least one of the weighting factors varies linearly with at least one of the one or more parameters.

21. The method of claim 17, wherein the at least one of the weighting factor varies non-linearly with at least one of the one or more parameters.

22. The method of claim 17, further comprising:

periodically determining the first and second weighting factors based on the one or more specified parameters, wherein the weighting factors vary over time, resulting in different weights being accorded the first data and second data over time; and

determining a plurality of blended solutions for the position of the vehicle over a period of time, the plurality of blended solutions describing a substantially continuous curve during a transition, over the period of time.

23. The method of claim 5, further comprising:

communicating with the first positioning device and the second positioning device using a single radio on the vehicle.

24. The method of claim 23, wherein communicating with the first positioning device and the second positioning device comprises communicating with each device in a different epoch on a common radio channel.

25. The method of claim 5, further comprising:

performing a transition, over time, from a state in which the second weighting factor disregards the second data in determining a blended solution for a position of the vehicle to a state in which the first weighting factor disregards the first data in determining a blended solution for a position of the vehicle.

26. The method of claim 25, wherein controlling operation of the vehicle comprises continuing operation of the vehicle without pause during the transition.

27. A system, comprising:

a processor; and

a non-transitory computer readable medium having encoded thereon a set of instructions that are executable by the processor to perform one or more operations, the set of instructions comprising;

instructions to receive, from a first positioning device at a first location, first data indicating an estimated position of a vehicle at a first point in time;

instructions to receive, from a second positioning device oriented at a second location, second data indicating an estimated position of the vehicle at the first point in time;

instructions to determine a first weighting factor for the first data and a second weighting factor for the second data, wherein the first and second weighting factors specify a relative weight to be accorded to each of the first and second data at the first point in time;

instructions to apply the first weighting factor to the first data;

instructions to apply the second weighting factor to the second data;

instructions to determine a blended solution for a first position of the vehicle at the first point in time, based at least in part on the first and second data and the first and second weighting factors; and

instructions to control operation of the vehicle, based on the determined first position of the vehicle.

28. A vehicle comprising the system of claim 27.

29. The system of claim 27, further comprising:

the first positioning device; and

the second positioning device.

30. The system of claim 29, wherein the first positioning device comprises a first total station and the second positioning device comprises a second total station.

31. An apparatus, comprising:

a non-transitory computer readable medium having encoded thereon a set of instructions that are executable by a computer to perform one or more operations, the set of instructions comprising;

instructions to receive, from a first positioning device at a first location, first data indicating an estimated position of a vehicle at a first point in time;

instructions to receive, from a second positioning device oriented at a second location, second data indicating an estimated position of the vehicle at the first point in time;

instructions to determine a first weighting factor for the first data and a second weighting factor for the second data, wherein the first and second weighting factors specify a relative weight to be accorded to each of the first and second data at the first point in time;

instructions to apply the first weighting factor to the first data;

instructions to apply the second weighting factor to the second data;

instructions to determine a blended solution for a first position of the vehicle at the first point in time, based at least in part on the first and second data and the first and second weighting factors; and

instructions to control operation of the vehicle, based on the determined first position of the vehicle.