Apparatus and method for an object measurement system

• US 5,590,060 A
• Filed: 11/15/1995
• Issued: 12/31/1996
• Est. Priority Date: 03/20/1992
• Status: Expired due to Term

• Current Assignee: HEIDENHAIN Corp. (Dr. Johannes Heidenhain GmbH)
• Original Assignee: Metronics, Inc.
• Inventors: Glasson, J. Peter, Granville, Gregg
• Primary Examiner(s): Ramirez, Ellis B.
• Assistant Examiner(s): MILLER, CRAIG S
• Application Number:
  US08/558,767
• Time in Patent Office: 412 Days
• Field of Search: 356/445, 356/446, 356/378, 356/394, 356/384, 356/371, 356/429, 356/430, 356/138, 382/106, 382/181, 382/190, 382/209, 395/50, 395/51, 395/919, 33/503-505, 33/545, 33/546, 364/167.01, 364/468, 364/188, 364/474.24-474.28, 364/474.29, 364/514 R, 364/552, 364/560, 318/570
• US Class Current: 702/155
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 7/008 using coordinate measuring machines

Abstract

An apparatus and method for an object measurement system is described which may be utilized in the inspection and measurement of various objects so as to obtain information regarding their features, dimensional measurements and tolerances. Various devices and methods for data point location and data entry are described which may be utilized in either manual and/or automatic modes of system operation. Input data is monitored so as to prevent erroneous data from being utilized and indication means are provided to notify a user or operator when erroneous data has been entered into the system. The present invention also provides a means by which the user or operator may enter point location data without having to preselect a feature type which is to be inspected and/or measured. The present invention also provides an apparatus and method for processing the point location data so as to determine the feature type therefrom within pre-specified error limits and without user pre-selection and for resolving ambiguities which may arise in the course of such processing. The user or operator may also override system operation if the feature type does not match the user'"'"'s or operator'"'"'s expected result. The system provides extensive user interaction capabilities and methods.

Claims

1. An object inspection system comprising:

an inspection station for holding an object to be measured;

a display monitor for viewing the object to be measured;

means for inputting at least one point location datum indicative of a point on the object;

processing means, responsive to the inputted point location data, for automatically determining if the inputted point location data represent a particular geometric feature type including a single point, two single points, a line, a circle, an arc, and an angle; and

means for displaying an indication of the geometric feature type determined to be represented by said inputted data.

2. The system of claim 1 in which said processing means further includes means for generating a single point if only one point location datum is entered and for determining the coordinates of said single point.

3. The system of claim 2 in which said means for displaying includes means for outputting the coordinates of a geometric feature determined to be a single point.

4. The system of claim 1 in which said processing means includes means for calculating the distance between two data points if only two data points are entered.

5. The system of claim 4 in which said means for displaying includes means for outputting the calculated distance between the two entered data points.

6. The system of claim 1 in which said processing means includes means for calculating, from the entered data points, whether the data points fit an equation for a line.

7. The system of claim 6 in which said processing means further includes means for calculating, from the entered data points, whether the data points fit an equation for a circle.

8. The system of claim 7 further including a stored maximum radius for a circle and means for determining if the data points entered define a circle with a radius greater than the stored maximum radius.

9. The system of claim 8 further including means for defining a line geometric form type if the entered data points form a circle with a radius greater than the stored maximum radius.

10. The system of claim 7 further including means for:

comparing the fit of the entered data points with an equation for a line and the fit of the entered data points with an equation for a circle, and

storing an indication of the equation with the best fit.

11. The system of claim 1 further including means for determining whether the entered data points form a circle or form an arc.

12. The system of claim 11 in which said means for determining includes means for analyzing if the entered data points were entered in order sequentially along an arc and, if not, storing a circle geometric form type.

13. The system of claim 11 further including a routine for determining if the entered data points were entered in order sequentially an arc and, if so, storing an arc geometric form type.

14. The system of claim 13 further including means for calculating the arc angle defined by said entered data points.

15. The system of claim 14 further including means for defining an arc geometric form type if said arc angle is between 15°

and 195° and

for defining a circle geometric form type if said arc angle is greater than 195°

.

16. The system of claim 1 further including means for determining if more than five data points have been entered.

17. The system of claim 16 further including means for determining if an odd number of data points have been entered and in response for eliminating an angle geometric form type from the possible geometric form types defined by said entered data points.

18. The system of claim 17 further including means for calculating:

a first line segment from the first half of the total data points entered, a second line segment from the second half of the total data points entered, and the angle between said first and second line segments.

19. The system of claim 18 further including means for storing a range of angles and for determining if said calculated angle falls within said range.

20. The system of claim 19 further including means for outputting a line geometric form type if said angle does not fall within said range.

21. An inspection system comprising:

means for holding an object to be inspected;

means for inputting at least one data point indicative of a point on a feature of the object;

processing means, responsive to the inputted data points, for automatically determining if a feature is a particular geometric form type including a single point, two single points, a line, a circle, an arc, and an angle.

22. The system of claim 21 in which said processing means includes a counter for counting the number of data points entered and means for classifying possible geometric form types based on the number of data points entered as follows:

space="preserve" listing-type="tabular">______________________________________ Data Points Possible Geometric Form Types ______________________________________ 1 a single point only 2 two single points only 3-5 one of a line, circle and arc 6,8,10,12 . . . one of an angle, line, circle, and arc 7,9,11,13 . . . one of a line, circle, and arc. ______________________________________

23. The system of claim 22 further including means for outputting the coordinates of the data point entered if the geometric form type is classified as a single point.

24. The system of claim 22 further including means for outputting the distance between two entered data points if the geometric form type is classified as two single points.

25. The system of claim 21 further including means for calculating the fit of the entered data points to an equation for a line, circle, and an arc and for storing said fit as a geometric form type error.

26. The system of claim 25 further including means for outputting the geometric form type with the smallest geometric form type error.

27. The system of claim 21 further including:

a stored maximum circle radius;

means for comparing the radius of a circle formed by the entered data points with the maximum circle radius criteria; and

means for setting the geometric form type to be a line if the radius of the circle formed by the entered data points exceeds the stored maximum circle radius.

28. The system of claim 21 further including:

means for determining the order of entry of the entered data points; and

mean for setting the geometric form type to be a circle if the data points are not sequentially entered in order along an arc.

29. The system of claim 28 further including;

means for storing a range of arc angles;

means for comparing the arc angle formed by the entered data points with the stored range of arc angles; and

means for setting the geometric form type to be an arc if the arc angle formed by the entered data points falls within said stored range of arc angles.

30. The system of claim 21 further including:

means for storing a range of angles;

means for comparing the angle form by the entered data points with the stored range of angles; and

means for setting the geometric form type to be an angle if the angle form by the entered data points falls within said stored range of angles.