Coordinate measurement machine with distance meter used to establish frame of reference

• US 8,898,919 B2
• Filed: 03/24/2014
• Issued: 12/02/2014
• Est. Priority Date: 01/20/2010
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Bridges, Robert E., Briggs, Clark H., Hoffer, John M. Jr.
• Primary Examiner(s): GUADALUPE, YARITZA
• Application Number:
  US14/223,067
• Publication Number:
  US 20140202016A1
• Time in Patent Office: 253 Days
• Field of Search: 335/03, 335/56, 335/58, 335/59, 33/1.M, 33/1.PT
• US Class Current: 33/503
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 21/047 Accessories, e.g. for positioning, for tool-setting, for measuring probes
• CPC Class Codes: G01B 2210/58 Wireless transmission of information between a sensor or probe and a control or evaluation unit
• CPC Class Codes: G01B 5/008 using coordinate measuring machines
• CPC Class Codes: G01B 5/012 Contact-making feeler heads therefor
• CPC Class Codes: G05B 19/401 characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/37193 Multicoordinate measuring system, machine, cmm
• CPC Class Codes: G05B 2219/40233 Portable robot
• CPC Class Codes: G05B 2219/40555 Orientation and distance
• CPC Class Codes: G05B 2219/45061 Measuring robot

Abstract

A portable articulated arm coordinate measuring machine includes a distance meter to measure 3D coordinates of at least three targets to establish a position and orientation of the articulated arm within a frame of reference established by the at least three targets.

Claims

1. A method of operating a portable articulated arm coordinate measuring machine (AACMM) for measuring three-dimensional coordinates of an object in space, comprising:

providing the AACMM in a AACMM frame of reference having an origin, the AACMM having a manually positionable arm portion, a base, a noncontact measurement device, and an electronic circuit, the arm portion having an opposed first end and second end, the arm portion including a plurality of connected arm segments, each of the plurality of connected arm segments including at least one position transducer for producing a plurality of position signals, the first end connected to the base, the noncontact measurement device connected to the second end, an electromagnetic radiation transmitter, and a sensor, the electronic circuit configured to receive the plurality of position signals;

providing a first reflective target at a first location having first target three-dimensional coordinates in a target frame of reference, a second reflective target at a second location having second target three-dimensional coordinates in the target frame of reference, and a third reflective target at a third location having third target three-dimensional coordinates in the target frame of reference, wherein the first location, the second location, and the third location are non-collinear;

manually positioning the second end to direct the transmitted electromagnetic radiation to the first target;

measuring a first distance to the first target with the noncontact measurement device and measuring a first plurality of position signals;

manually positioning the second end to direct the transmitted electromagnetic radiation to the second target;

measuring a second distance to the second target with the noncontact measurement device and measuring a second plurality of position signals;

manually positioning the second end to direct the transmitted electromagnetic radiation to the third target;

measuring a third distance to the third target with the noncontact measurement device and measuring a third plurality of position signals;

determining by a processor, relative to the target frame of reference, first origin coordinates and first AACMM orientation angles, the first origin coordinates being three-dimensional coordinates of the first origin in the target frame of reference and the first AACMM orientation angles being three rotational angles of orientation of the first AACMM in the target frame of reference, the first origin coordinates and the first AACMM orientation angles being based at least in part on the first distance, the first plurality of signals, the first three-dimensional coordinates, the second distance, the second plurality of signals, the second three-dimensional coordinates, the third distance, the third plurality of signals, and the third three-dimensional coordinates; and

storing the first origin coordinates and the first AACMM orientation angles.

2. The method of claim 1 wherein, in the step of providing a first reflective target, the first reflective target is a retroreflector.

3. The method of claim 1 wherein, in the step of providing a first reflective target, the first reflective target is a non-cooperative target.

4. The method of claim 1 wherein, in the step of providing the AACMM, the AACMM has a contact measurement device connected to the second end and the electronic circuit is further configured to determine a position of the contact measurement device.

5. The method of claim 4 wherein, in the step of providing the AACMM, the contact measurement device is a probe tip.

6. The method of claim 4, further comprising:

touching the contact measurement device to a feature of the object; and

measuring fourth three-dimensional coordinates of the feature in the target frame of reference, the fourth three-dimensional coordinates based at least in part on the determined position of the contact measurement device, the determined first origin coordinates, and the determined first AACMM orientation angles.

7. The method of claim 1, further comprising:

manually positioning the second end to direct the transmitted electromagnetic radiation to a fourth reflective target;

measuring a fourth distance to the fourth reflective target with the noncontact measurement device and measuring a fourth plurality of position signals; and

determining by the processor, relative to the target frame of reference, three-dimensional coordinates of the fourth reflective target, based at least in part on the measured fourth distance, the measured fourth plurality of position signals, the determined first origin coordinates, and the determined first AACMM orientation angles.

8. The method of claim 1, further comprising:

moving the AACMM, relative to the target frame of reference, to second origin coordinates and second AACMM orientation angles,

manually positioning the second end to direct the transmitted electromagnetic radiation to the first target;

measuring a fourth distance to the first target with the noncontact measurement device and measuring a fourth plurality of position signals;

manually positioning the second end to direct the transmitted electromagnetic radiation to the second target;

measuring a fifth distance to the second target with the noncontact measurement device and measuring a fifth plurality of position signals;

manually positioning the second end to direct the transmitted electromagnetic radiation to the third target;

measuring a sixth distance to the third target with the noncontact measurement device and measuring a sixth plurality of position signals;

determining by the processor, relative to the target frame of reference, second origin coordinates and second AACMM orientation angles, the second origin coordinates being three-dimensional coordinates of the origin in the target frame of reference and the second AACMM orientation angles being three rotational angles of orientation of the AACMM in the target frame of reference, the second origin coordinates and the second AACMM orientation angles being based at least in part on the fourth distance, the fourth plurality of signals, the first three-dimensional coordinates, the fifth distance, the fifth plurality of signals, the second three-dimensional coordinates, the sixth distance, the sixth plurality of signals, and the third three-dimensional coordinates; and

storing the second origin coordinates and the second AACMM orientation angles.