METHOD FOR EVALUATING MOUNTING STABILITY OF ARTICULATED ARM COORDINATE MEASUREMENT MACHINE USING INCLINOMETERS

• US 20110178766A1
• Filed: 01/14/2011
• Published: 07/21/2011
• Est. Priority Date: 01/20/2010
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Bailey, Brent, York, Frederick John
• Granted Patent: US 9,009,000 B2
• Time in Patent Office: Days
• US Class Current: 702/154
• CPC Class Codes: G01B 11/007 feeler heads therefor
• CPC Class Codes: G01B 21/047 Accessories, e.g. for positioning, for tool-setting, for measuring probes
• 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 19/406 characterised by monitoring or safety G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/24067 Processor stores variables, events and date in eeprom, for external monitor
• CPC Class Codes: G05B 2219/37193 Multicoordinate measuring system, machine, cmm
• CPC Class Codes: G05B 2219/40233 Portable robot
• CPC Class Codes: G05B 2219/40596 Encoder in each joint
• CPC Class Codes: G05B 2219/45061 Measuring robot

Abstract

A portable articulated arm coordinate measurement machine can include a base, a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, an electronic circuit that receives the position signals from the transducers, a first inclinometer coupled to the base, wherein the inclinometer is configured to produce a first electrical signal responsive to an angle of tilt of the base and an electrical system configured to record a first reading of the first inclinometer and a second reading of the first inclinometer, wherein the first reading is in response to at least one of a first force applied to the base and a third force applied to the mounting structure, wherein the second reading is in response to at least one of a second force applied to the base and a fourth force applied to the mounting structure.

Claims

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

a base;

a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, each of the arm segments including at least one position transducer for producing a position signal, the arm portion being coupled to the base, wherein the base is attached to a mounting structure;

an electronic circuit that receives the position signals from the transducers;

a first inclinometer coupled to the base, wherein the inclinometer is configured to produce a first electrical signal responsive to an angle of tilt of the base; and

an electrical system configured to record a first reading of the first inclinometer and a second reading of the first inclinometer, wherein the first reading is in response to at least one of a first force applied to the base and a third force applied to the mounting structure and wherein the second reading is in response to at least one of a second force applied to the base and a fourth force applied to the mounting structure,

wherein the electrical system is further configured to determine a parameter of base stability based on the difference between the first and second readings of the first inclinometer.

2. The AACMM as claimed in claim 1 wherein the first force is generated by a first spatial arrangement of the plurality of connected arm segments and the second force is generated by a second spatial arrangement of the plurality of connected arm segments.

3. The AACMM as claimed in claim 2 wherein the parameter of base stability is further based on a first transducer reading in the first spatial arrangement and a second transducer reading in the second spatial arrangement.

4. The AACMM as claimed in claim 3 wherein the electrical system is further configured to display the parameter of base stability.

5. The AACMM as claimed in claim 4 further comprising a first processor configured to direct the movement of the plurality of connected arm segments to the first spatial arrangement and the second spatial arrangement.

6. The AACMM as claimed in claim 3 further comprising a second processor configured to issue an alarm in response to a range of values for the parameter of base stability, wherein the alarm is at least one of an audio alarm, a visible alarm, or a second electrical signal sent to an electronic device.

7. The AACMM as claimed in claim 1 wherein the first inclinometer measures the angle of tilt of the base along at least two axes.

8. The AACMM as claimed in claim 1 wherein a second inclinometer is coupled to the mounting structure and is configured to produce a third electrical signal responsive to an angle of tilt of the mounting structure.

9. The AACMM as claimed in claim 8 wherein the second inclinometer measures the angle of tilt of the mounting structure along at least two axes.

10. The AACMM as claimed in claim 8 wherein the electrical system is further configured to record a third reading of the second inclinometer in response to a third force applied to the mounting structure, record a fourth reading of the second inclinometer in response to a fourth force applied to the mounting structure, and determine a parameter of mounting structure stability based on the difference between the third and fourth readings of the second inclinometer.

11. The AACMM as claimed in claim 10 wherein the electrical system is further configured to display at least two of the following:

the parameter of base stability, the parameter of mounting structure stability, and a difference between the parameter of base stability and the parameter of mounting structure stability.

12. The AACMM as claimed in claim 10 wherein the electrical system is further configured to analyze the first, second, third, and fourth readings to determine whether the base is securely attached to the mounting structure.

13. A method of evaluating the mounting stability of a portable articulated arm coordinate measuring machine (AACMM), the method comprising the steps of:

providing a base;

providing a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, each arm segment including at least one position transducer for producing a position signal, the arm portion being coupled to the base, wherein the base is attached to a mounting structure;

providing an electronic circuit that receives the position signals from the transducers;

providing a first inclinometer coupled to the base, wherein the first inclinometer is configured to produce a first electrical signal responsive to an angle of tilt of the base;

providing an electrical system configured to record a first reading of the first inclinometer and a second reading of the first inclinometer;

recording the first reading in response to at least one of a first force applied to the base and a third force applied to the mounting structure;

recording the second reading in response to at least one of a second force applied to the base and a fourth force applied to the mounting structure;

determining a parameter of base stability based on the difference between the first and second readings of the first inclinometer; and

recording the parameter of base stability.

14. The method as claimed in claim 13 further comprising the steps of:

moving the plurality of connected arm segments into a first spatial arrangement to generate the first force; and

moving the plurality of connected arm segments into a second spatial arrangement to generate the second force.

15. The method as claimed in claim 14 wherein the parameter of base stability is further based on a first transducer reading in the first spatial arrangement and a second transducer reading in the second spatial arrangement.

16. The method as claimed in claim 15 further comprising a step of displaying the parameter of base stability.

17. The method as claimed in claim 16 further comprising the steps of directing the movement of the plurality of connected arm segments to the first spatial arrangement and the second spatial arrangement.

18. The method as claimed in claim 15 further comprising a step of issuing an alarm.

19. The method as claimed in claim 13 further comprising the step of measuring with the first inclinometer the angle of tilt of the base along at least two axes.

20. The method as claimed in claim 13 further comprising a step of providing a second inclinometer coupled to the mounting structure and configured to produce a second electrical signal responsive to an angle of tilt of the mounting structure.

21. The method as claimed in claim 20 further comprising the step of measuring with the second inclinometer the angle of tilt of the mounting structure along at least two axes.

22. The method as claimed in claim 20 further comprising the steps of:

applying a third force to the mounting structure;

recording a third reading of the second inclinometer;

applying a fourth force to the mounting structure;

recording a fourth reading of the second inclinometer; and

determining a parameter of mounting structure stability based on the difference between the third and fourth readings of the second inclinometer.

23. The method as claimed in claim 22 further comprising the step of displaying at least two of the following:

the parameter of base stability, the parameter of mounting structure stability, and a difference between the parameter of base stability and the parameter of mounting structure stability.

24. The method as claimed in claim 22 further comprising the step of analyzing the first, second, third, and fourth readings to determine whether the base is securely attached to the mounting structure.

25. A computer program product for implementing a portable articulated arm coordinate measuring machine (AACMM), the computer program product comprising a storage medium having computer-readable program code embodied thereon, which when executed by a computer causes the computer to implement a method, the method including:

providing a base;

providing a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, each arm segment including at least one position transducer for producing a position signal, the arm portion being coupled to the base, wherein the base is attached to a mounting structure;

providing an electronic circuit that receives the position signals from the transducers;

providing a first inclinometer coupled to the base, wherein the inclinometer is configured to produce a first electrical signal responsive to an angle of tilt of the base;

providing an electrical system configured to record a first reading of the first inclinometer and a second reading of the first inclinometer;

recording the first reading in response to at least one of a first force applied to the base and a third force applied to the mounting structure;

recording the second reading in response to at least one of a second force applied to the base and a fourth force applied to the mounting structure;

determining a parameter of base stability based on the difference between the first and second readings of the first inclinometer; and

recording the parameter of base stability.

26. The computer program product as claimed in claim 25 wherein the method further comprises the steps of:

moving the plurality of connected arm segments into a first spatial arrangement to generate the first force; and

moving the plurality of connected arm segments into a second spatial arrangement to generate the second force.

27. The computer program product as claimed in claim 26 wherein the parameter of base stability is further based on a first transducer reading in the first spatial arrangement and a second transducer reading in the second spatial arrangement.

28. The computer program product as claimed in claim 27 wherein the electrical system is further configured to display the parameter of base stability.

29. The computer program product as claimed in claim 28 wherein the method further comprises the steps of directing the movement of the plurality of connected arm segments to the first spatial arrangement and the second spatial arrangement.

30. The computer program product as claimed in claim 27 wherein the method further comprises a step of issuing an alarm.

31. The computer program product as claimed in claim 25 wherein the method further comprises a step of providing a second inclinometer coupled to the mounting structure and configured to produce a second electrical signal responsive to an angle of tilt of the mounting structure.

32. The computer program product as claimed in claim 31 wherein the method further comprises the steps of:

applying a third force to the mounting structure;

recording a third reading of the second inclinometer;

applying a fourth force to the mounting structure;

recording a fourth reading of the second inclinometer; and

determining a parameter of mounting structure stability based on the difference between the third and fourth readings of the second inclinometer.