Portable coordinate measurement machine

• US 8,607,467 B2
• Filed: 12/17/2012
• Issued: 12/17/2013
• Est. Priority Date: 02/14/2002
• Status: Expired due to Term

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Raab, Simon
• Primary Examiner(s): Bennett, G. Bradley
• Application Number:
  US13/716,274
• Publication Number:
  US 20130104411A1
• Time in Patent Office: 365 Days
• Field of Search: 33/1.PT, 335/03, 335/56, 335/57, 335/58
• US Class Current: 33/503
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 21/042 Calibration or calibration artifacts G01B3/30, G01B9/02072 take precedence
• CPC Class Codes: G01B 5/008 using coordinate measuring machines
• CPC Class Codes: G01B 7/008 using coordinate measuring machines
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• 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 2219/45061 Measuring robot

Abstract

A portable articulated arm coordinate measurement machine is provided. An articulated arm is provided having a plurality of arm segments. Each arm segment includes an angular encoder for producing a signal corresponding to an angle of rotation. A shaft rotates which about an axis is attached to an inner portion of a first and second bearing. A patterned disk is attached to the shaft. A housing is attached to an outer portion of the first and second bearing. A read head is attached to the housing in proximity to the patterned disk which produces an electrical signal in response to an angle of rotation. The patterned disk and the first arm segment supported for rotation about the axis by only the first and second bearing. A circuit receives the electrical signal and provides an angle and data corresponding to a position of the probe.

Claims

1. A portable articulated arm coordinate measurement machine, comprising:

a manually positionable articulated arm having opposed first and second ends, the articulated arm including a plurality of connected arm segments, the plurality of arm segments including a first arm segment, each arm segment including at least one angular encoder for producing a signal corresponding to an angle of rotation;

a base section connected to the second end;

a probe connected to the first end;

a shaft fixedly attached to an inner portion of a first bearing and an inner portion of a second bearing, the shaft configured to rotate about an axis passing substantially through a center of the first bearing and a center of the second bearing, the shaft configured to fixedly couple with the first arm segment;

a patterned disk fixedly attached to the shaft, the patterned disk having a periodic pattern of a measurable characteristic;

a housing fixedly attached to an outer portion of the first bearing and an outer portion of the second bearing;

a read head fixedly attached to the housing, the read head in proximity to the patterned disk, the read head configured to produce an electrical signal in response to an angle of rotation about the axis of the shaft relative to the housing, the patterned disk and the first arm segment supported for rotation about the axis by only the first bearing and the second bearing; and

an electrical circuit configured to receive the electrical signal, to provide an angle based at least in part on the electrical signal, and to provide data corresponding to a position of the probe, the data based at least in part on the angle.

2. The portable articulated arm coordinate measurement machine of claim 1 wherein the axis defines an axis of rotation for a swivel joint.

3. The portable articulated arm coordinate measurement machine of claim 1 wherein the axis defines an axis of rotation for a hinge joint.

4. The portable articulated arm coordinate measurement machine of claim 1 wherein the patterned disk is in optical communication with the read head.

5. The portable articulated arm coordinate measurement machine of claim 1 wherein the patterned disk includes a feature having a characteristic measurable by the read head selected from the group consisting of:

reflectivity characteristic, opacity characteristic, magnetic field characteristic, capacitance characteristic, inductance characteristic and surface roughness characteristic.

6. A portable articulated arm coordinate measurement machine, comprising:

a manually positionable articulated arm having opposed first and second ends, the articulated arm including a plurality of connected arm segments, the plurality of arm segments including a first arm segment, each arm segment including at least one angular encoder for producing a signal corresponding to an angle of rotation;

a base section connected to the second end;

a probe connected to the first end;

a shaft fixedly attached to an inner portion of a first bearing and an inner portion of a second bearing, the shaft configured to rotate about an axis passing substantially through a center of the first bearing and a center of the second bearing, the shaft configured to fixedly couple with the first arm segment;

a read head fixedly attached to the shaft;

a housing fixedly attached to an outer portion of the first bearing and an outer portion of the second bearing;

a patterned disk fixedly attached to the housing, the patterned disk having a periodic pattern of a measurable characteristic, the patterned disk arranged in proximity to the read head, the patterned disk configured to produce an electrical signal in response to an angle of rotation about the axis of the shaft relative to the housing, the read head and the first arm segment supported for rotation about the axis by only the first bearing and the second bearing; and

an electrical circuit configured to receive the electrical signal, to provide an angle based at least in part on the electrical signal, and to provide data corresponding to a position of the probe, the data based at least in part on the angle.

7. The portable articulated arm coordinate measurement machine of claim 6 wherein the axis defines an axis of rotation for a swivel joint.

8. The portable articulated arm coordinate measurement machine of claim 6 wherein the axis defines an axis of rotation for a hinge joint.

9. The portable articulated arm coordinate measurement machine of claim 6 wherein the patterned disk is in optical communication with the read head.

10. The portable articulated arm coordinate measurement machine of claim 6 wherein the patterned disk includes a feature having a characteristic measurable by the read head selected from the group consisting of:

reflectivity characteristic, opacity characteristic, magnetic field characteristic, capacitance characteristic, inductance characteristic and surface roughness characteristic.