Thermal management of an optical scanning device

Patent metadata

Field	Value
Publication number	US-11022434-B2
Application number	US-201816188927-A
Country	US
Kind code	B2
Filing date	Nov 13, 2018
Priority date	Nov 13, 2017
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

Thermal variations on an optical scanning device can affect measurements made by that device. Various ways are presented here to control the temperature of a device and compensate for temperature variations of the device.

First claim

What is claimed is:

1. A method of controlling the measurement of coordinate data by an optical scanning device according to a thermal status of the optical scanning device, the method comprising:
preventing the use of the optical scanning device to measure coordinate data when the optical scanning device is substantially outside of thermal equilibrium; and
allowing the optical scanning device to measure coordinate data when the optical scanning device is substantially within thermal equilibrium.

2. The method of claim 1 , further comprising:
regularly measuring a temperature of the optical scanning device at one or more positions,
wherein the optical scanning device being substantially outside of thermal equilibrium is determined using at least the measured temperature; and
wherein the optical scanning device being substantially within thermal equilibrium is determined using at least the measured temperature.

3. The method of claim 2 , further comprising displaying to a user a current thermal status of the device, based at least on the measured temperature.

4. The method of claim 3 , further comprising allowing the optical scanning device to measure coordinate data after a user acknowledges the thermal status.

5. The method of claim 3 , further comprising displaying to a user an estimated time until the device will substantially be within thermal equilibrium.

6. The method of claim 2 , further comprising adjusting measured coordinate data based at least on the measured temperature.

7. The method of claim 2 , wherein the optical scanning device is substantially within thermal equilibrium when the temperature remains stable for one minute.

8. The method of claim 1 , wherein the optical device is considered to be outside of thermal equilibrium for a predetermined period of time after the optical scanning device has been powered-on or woken from a sleep mode and is otherwise ready to measure coordinate data.

9. The method of claim 8 , wherein the predetermined period of time is at least one minute.

10. The method of claim 8 , wherein the predetermined period of time is based at least on an expected time to reach thermal equilibrium.

11. The method of claim 8 , wherein the predetermined period of time is based at least on an initial temperature of the device.

12. The method of claim 1 , further comprising:
when the optical scanning device is substantially within thermal equilibrium, actuating the optical scanning device to project a pattern of light onto an object to be measured with a projector on the optical scanning device;
imaging the object having the pattern of light with one or more cameras on the optical scanning device;
measuring a temperature of the optical scanning device at one or more positions on the optical scanning device; and
measuring geometric coordinates on the object based at least on images from the one or more cameras and the measured temperature.

13. The method of claim 12 , wherein measuring a temperature comprises measuring a temperature of the optical scanning device at two or more positions on the optical scanning device.

14. The method of claim 13 , wherein measuring a temperature comprises measuring a temperature of the optical scanning device at four or more positions on the optical scanning device.

15. The method of claim 12 , further comprising storing both the coordinate data and a corresponding measured temperature.

16. The method of claim 12 , wherein measuring geometric coordinates on the object is also based at least on previously measured geometric coordinates at a temperature substantially similar to the measured temperature.

17. The method of claim 1 , wherein:
the optical scanning device comprises:
a projector configured to illuminate a portion of an object to be measured with a pattern of light;
one or more cameras configured to capture images of the portion of the object illuminated by the projector;
a mounting section; and
a warming cradle comprising a mounting section configured to form an electrical and physical connection with the mounting section of the optical scanning device and to provide electrical power and data transfer capabilities to the optical scanning device,

wherein the optical scanning device is configured to raise its temperature to a temperature above ambient temperature while connected to the warming cradle.

18. The method of claim 17 , wherein the physical connection comprises a kinematic mount.

19. The method of claim 17 , wherein the optical scanning device is configured to change its operating state away from a measuring state when connected to the warming cradle.

20. The method of claim 17 , wherein the warming cradle is configured to lift the optical scanning device.

21. The method of claim 17 , wherein the warming cradle forms a thermal connection with the optical scanning device to efficiently transfer heat to the optical scanning device.

22. The method of claim 1 , wherein the optical scanning device is a handheld optical scanning device.

23. The method of claim 1 , wherein the optical scanning device comprises a plurality of fans.

24. The method of claim 1 , wherein the optical scanning device comprises:
a projector configured to illuminate a portion of an object to be measured with a pattern of light;
one or more cameras configured to capture images of the portion of the object illuminated by the projector;
a temperature sensor configured to measure a temperature of the optical scanning device at one or more positions;
a fan; and
at least one processor in communication with the temperature sensor and the fan, the processor configured to control the fan based at least on data from the temperature sensor.

25. The method of claim 24 , wherein the optical scanning device comprises a plurality of temperature sensors spaced sufficiently distant from each other to indicate spatial temperature variations on the optical scanning device.

26. The method of claim 24 , wherein the at least one processor is configured to control at least two fans individually, based at least on data from at least two temperature sensors.

27. The method of claim 24 , wherein the optical scanning device comprises a dustproof and waterproof enclosure.

28. The method of claim 24 , further comprising at least one heat exchanger disposed such that the fan urges air flow over the heat exchanger.

29. The method of claim 28 , further comprising at least one heat pipe thermally connecting at least one of a camera and the projector to the heat exchanger, the at least one heat pipe comprising a fluid that evaporates to transfer heat from a heat source to the heat exchanger and condenses back to a fluid at the heat exchanger.

30. The method of claim 24 , wherein the control of the fan uses a proportional-integral-derivative control system.

31. The method of claim 24 , wherein the fan urges air flow in from and out toward a rearward-facing portion of the optical scanning device.

32. The method of claim 24 , further comprising a pistol grip handle.

33. The method of claim 1 , comprising:
measuring a temperature of the optical scanning device at one or more positions; and
operating a fan at least according to the measured temperature to maintain a substantially consistent temperature of the optical scan

Assignees

• Hexagon Metrology Inc

Inventors

• Bauer Tom
• Gerent Gerald
• Demiter David

Classifications

• G01B5/0014

  due to temperature (on machine tools B23Q11/0003) · CPC title

• G01B11/2513 Primary

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title

• G01B21/04

  by measuring coordinates of points · CPC title

• H04N1/02481

  Arrangements for positioning elements within a head (H04N1/02409 takes precedence) · CPC title

• G01B11/14

  for measuring distance or clearance between spaced objects or spaced apertures (G01B11/26 takes precedence; rangefinders G01C3/00) · CPC title