Method and apparatus for numerically controlled probing

• US 5,796,619 A
• Filed: 02/15/1996
• Issued: 08/18/1998
• Est. Priority Date: 02/15/1996
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Wampler, Robert R.
• Primary Examiner(s): Gordon, Paul P.
• Application Number:
  US08/602,257
• Time in Patent Office: 915 Days
• Field of Search: 364/474.37, 364/571.05, 364/559, 364/551.01, 364/552, 364/474.02, 364/474.29, 364/474.35, 364/474.36, 318/568, 318/572, 318/569, 33/559, 235/151.11
• US Class Current: 700/195
• CPC Class Codes: G05B 19/41 characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path G05B19/25, G05B19/31, G05B19/37, G05B19/39, G05B19/40 take precedence
• CPC Class Codes: G05B 2219/35131 Generate polynomial surface
• CPC Class Codes: G05B 2219/37043 Touch probe, store position of touch point on surface
• CPC Class Codes: G05B 2219/49344 Surface, 5-axis surface machining

Abstract

A probing system used for determining a measured set of dimensions of at least one feature of an object. The system comprises an input device that receives an ideal set of dimension of the at least one feature. The input device generates a first signal indicative of an amount and location of sample measurements taken of the at least one feature. The system also comprises a probe device, which is electrically connected to the input device. The probe device receives the first signal from the input device, and in response directs a probe to the location of the measurements to be taken for each of the amount of sample measurements indicated. The probe device outputs a second signal indicative of a measured location for each of the amount of samples taken. The system further comprises a processor electrically connected to the probe device. The processor receives the second signal indicative of the measured locations of each of the samples taken, and rotates the measured locations about a single sample so all samples can be represented as a point lying on a two dimensional plane. Further, the processor uses the rotated samples to calculate a set of rotated dimensions, and then counter-rotates the rotated dimensions back to the positions of the measured locations to determine the measured set of dimensions of the feature.

Claims

1. A probing system for determining a measured set of dimensions of at least one feature of an object, said system comprising:

an input device that receives an ideal set of dimension of the at least one feature, said input device generating a first signal indicative of an amount of samples and a location of each of the samples of the at least one feature;

a probe device, electrically connected to said input device, said probe device receiving the first signal from said input device, and in response directing a probe to the location of each of the samples, said probe device outputting a second signal indicative of measured three-dimensional locations of the samples; and

a processor electrically connected to said probe device, said processor receiving the second signal indicative of the measured three-dimensional locations of the samples, said processor operating upon said second signal to numerically rotate the three-dimensional measured locations about a single one of the samples until each of the samples is numerically represented as a point lying on a single two dimensional plane, said processor using the numerically rotated samples to calculate a set of rotated dimensions, said processor then operating on said rotated dimensions to numerically counter-rotate said rotated dimensions about the single one of the samples to determine the measured set of dimensions.

2. The probing system of claim 1, wherein said input device includes a computer aided design system that receives the ideal set of dimensions, and converts them to a series of high level instructions;

and

a post processor in communication with the computer aided design system that converts the series of high level instructions to said first signal indicative of the amount of samples and the location of the samples of the at least one feature.

3. The probing system of claim 1, wherein said probing device includes a numerically controlled device having a machine control unit that controls the directing of the probe to the location of each of the samples and outputs the second signal indicative of the measured locations of the samples.

4. The probing system of claim 3, wherein said numerically controlled device further including a plurality of encoders that report the measured locations to the machine control unit, when the probe contacts the object while moving to the location of each of the samples.

5. The probing system of claim 3, wherein said numerically controlled device is a computer numerically controlled device having a memory that stores the location of each of the samples made by said probing device.

6. The probing system of claim 3, wherein said numerically controlled device is operable in at least five axes.

7. The probing system of claim 6, wherein said numerically controlled device performs machining operations on said object.

8. The probing system of claim 7, wherein said numerically controlled device performs drilling on said object.

9. The probing system of claim 1 further including a display monitor in communication with said processor for displaying the set of dimensions of the at least one feature and comparing the measured set of dimensions with the ideal set of dimensions.

10. A method for determining a measured set of dimensions of at least one feature of an object, said method comprising the steps of:

inputting an ideal set of dimensions of the at least one feature;

generating an amount and location of samples taken of the at least one feature based on the ideal set of dimensions;

directing a probe to the location of the samples;

outputting measured location points, each representing a three-dimensional location, where the probe makes contact with the object;

calculating a numerical rotation of the measured location points, each of the points corresponding to one of the samples, about a designated one of the measured location points until each of the rotated location points is lying on a two dimensional plane;

calculating a rotated measured set of dimensions using the numerically rotated location points; and

calculating a numerical counter-rotation of the rotated measured set of dimensions around the designated one of the location points to determine the measured set of the dimensions.

11. The method for determining a measured set of dimensions according to claim 10 wherein said step of calculating a numerical rotation of each of the measured locations includes the steps of:

calculating a numerical rotation of the measured location points around the designated one of the location points until the measured location points are parallel with one axis then designating the measured location points as partially rotated points; and

calculating a numerical rotation of the partially rotated points around the designated one of the measured location points until the partially rotated points lie within one plane then designating the partially rotated points as the rotated location points.

12. The method for determining a measured set of dimensions according to claim 11, wherein the partially rotated points are parallel to the Y-axis.

13. The method for determining a measured set of dimensions according to claim 11, wherein the one plane is an X-Y plane.

14. The method for determining a measured set of dimensions according to claim 10, wherein said step of calculating a rotated measured set of dimensions includes a least squares algorithm.

15. The method for determining a measured set of dimensions according to claim 10, wherein said step of calculating a numerical counter-rotation of the rotated measured set of dimensions includes the steps of:

calculating a numerical counter-rotation of the rotated measured set of dimensions around the designated one of the measured location points until the measured set of dimensions are parallel with one axis, then designating the measured set of dimensions as the partially counter-rotated measured set of dimensions; and

calculating a numerical counter-rotation of the partially counter-rotated measured set of dimensions around the designated one of the location points until the partially counter-rotated points lie in a plane of the location points, then designating the partially counter-rotated points as the measured set of the dimensions.

16. A method of simplifying a calculation of a series of three-dimensional data points sampled along 5 axes of a Numerically Controlled machine by repositioning the series of three-dimensional data points such that each of the data points is lying along a plane defined by an X and Y axes, allowing the calculation of a measured set of dimensions by the Numerically Controlled machine to be performed rapidly, said method comprising the steps of:

designating a first point of the data points sampled along the 5 axes of the Numerically Controlled machine as an origin for defining each remaining one of the data points in polar coordinates;

calculating a numerical rotation of each of the data points by some angle, except the first point, around the origin until all newly positioned points are parallel with the Y-axes of the Numerically Controlled machine; and

calculating a numerical rotation of the rotated newly positioned data points around the origin until the series of data points is lying along the plane defined by the X and Y axes of the Numerically Controlled machine.