Method and apparatus for following an operator and locking onto a retroreflector with a laser tracker

• US 9,885,559 B2
• Filed: 03/06/2017
• Issued: 02/06/2018
• Est. Priority Date: 04/21/2010
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Nagalla, Kalyan, Mehler, Robert C., Bridges, Robert E.
• Primary Examiner(s): Punnoose, Roy M
• Application Number:
  US15/450,200
• Publication Number:
  US 20170176169A1
• Time in Patent Office: 337 Days
• Field of Search: 356 401, 356138, 35613903, 35613904, 3561411, 3561412, 3561415, 3561523, 356154, 356498, 356614, 356620, 356622, 356623, 702150, 702151, 702152, 702153
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 21/047 Accessories, e.g. for positioning, for tool-setting, for measuring probes
• CPC Class Codes: G01B 5/004 for measuring coordinates of points
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 3/786 the desired condition being maintained automatically
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

A method for measuring three-dimensional (3D) coordinates includes providing a retroreflector and a laser tracker. In a first instance, an operator gives a follow-operator command. The laser tracker responds by following movement of the operator. In a second instance, the operator gives a lock-on command. The laser tracker responds by steering a beam of light onto the retroreflector.

Claims

1. A three-dimensional (3D) coordinate measurement system, comprising:

a retroreflector;

a laser tracker including;

a first light source;

a second light source;

at least one camera proximate the second light source; and

a processor responsive to executable instructions which when executed by the processor is operable to;

in a first instance, determine that a follow-operator command has been given by an operator and in response turn the laser tracker to follow movement of the operator; and

in a second instance, determine that a lock-on command has been given by the operator and in response, steer a beam of light from the first light source onto the retroreflector.

2. The system of claim 1 wherein the follow-operator command is at least one of:

a movement of the retroreflector in space; and

, a temporal change in returned light from the retroreflector.

3. The system of claim 2 wherein the laser tracker is further configured to illuminate the retroreflector with the second light source during the follow-operator command and to capture an image of the illuminated retroreflector in response.

4. The system of claim 2 wherein the follow-operator command is performed with the retroreflector held in a hand of the operator.

5. The system of claim 1 wherein the lock-on command is at least one of:

a movement of the retroreflector in space; and

, a temporal change in returned light from the retroreflector.

6. The system of claim 5 wherein the laser tracker is further configured to illuminate the retroreflector during the lock-on command with the second light source and to capture an image of the illuminated retroreflector in response.

7. The system of claim 5 wherein the lock-on command is performed with the retroreflector held in a hand of the operator.

8. The system of claim 1 wherein at least one of the follow-operator command and the lock-on command is based on a position of an arm of the operator relative to a torso of the operator.

9. The system of claim 1 wherein the processor is further responsive to executable instructions which when executed by the processor is operable to, in the second instance, track movement of the retroreflector with the beam of light following the lock-on command.

10. The system of claim 1 wherein the processor is further responsive to executable instructions which when executed by the processor is operable to, in the second instance, determine 3D coordinates of the retroreflector following the lock-on command.

11. A method for measuring three-dimensional (3D) coordinates comprising:

providing a retroreflector and a laser tracker, the laser tracker including a first light source, a second light source, at least one camera proximate the second light source, and a processor;

in a first instance;

giving by an operator a follow-operator command;

responding with the processor, executing executable instructions, to the follow-operator command by turning the laser tracker to follow movement of the operator;

in a second instance;

giving by the operator a lock-on command;

responding with the processor, executing executable instructions, to the lock-on command by steering a beam of light from the first light source onto the retroreflector.

12. The method of claim 11 wherein, in giving the follow-operator command, the follow-operator command is at least one of:

a movement of the retroreflector in space; and

, a temporal change in returned light from the retroreflector.

13. The method of claim 12 wherein, during the follow-operator command, the laser tracker illuminates the retroreflector with the second light source and captures an image of the illuminated retroreflector in response.

14. The method of claim 12 wherein the follow-operator command is performed with the retroreflector held in a hand of the operator.

15. The method of claim 11 wherein, in giving by the operator a lock-on command, the lock-on command is at least one of:

a movement of the retroreflector in space; and

, a temporal change in returned light from the retroreflector.

16. The method of claim 15 wherein, during the lock-on command, the laser tracker illuminates the retroreflector with the second light source and captures an image of the illuminated retroreflector in response.

17. The method of claim 15 wherein, in the second instance, the lock-on command is performed with the retroreflector held in a hand of the operator.

18. The method of claim 11 wherein at least one of the follow-operator command and the lock-on command is based on a position of an arm of the operator relative to a torso of the operator.

19. The method of claim 11 wherein, following the second instance, the laser tracker tracks movement of the retroreflector with the beam of light.

20. The method of claim 11 wherein, following the second instance, the laser tracker determines 3D coordinates of the retroreflector.