Acquiring dimensions of a large object

• US 4,937,766 A
• Filed: 07/23/1987
• Issued: 06/26/1990
• Est. Priority Date: 07/23/1986
• Status: Expired due to Fees

• Current Assignee: Mannesmann AG (Vodafone Group PLC)
• Original Assignee: Mannesmann AG (Vodafone Group PLC)
• Inventors: Schoenartz, Norbert, Fister, Wilhelm, Deppe, Gerd-Joachim
• Primary Examiner(s): Gruber, Felix D.
• Assistant Examiner(s): Mattson, Brian M.
• Application Number:
  US07/077,418
• Time in Patent Office: 1,069 Days
• Field of Search: 364/560, 364/562-564, 250/560, 250/306, 250/307, 356/379, 356/381-384, 356/376, 358/107, 382/25
• US Class Current: 382/154
• CPC Class Codes: G01B 11/2441 using interferometry

Abstract

A method of acquiring dimensional and gauge data of objects and work pieces, such as forgings or the like, uses two image producing sensors, each being up and down tiltable about a horizontal axis and swivable from side to side about a vertical axis. At least one of the sensors is directed initially towards the object for acquiring position data on a particular point of the object such as a point of intersection of two contrast lines. One of these sensors is then positioned, including tilting and/or swiveling until a particular image field point coincides with the intersection point whereupon the other sensor has a particular image field point trained on that same particular intersection point. Finally, dimensional and guage data of the object is derived from angular position data of multiple points as so acquired by the two sensors.

Claims

1. Method of contactless acquiring dimensional and gauge data of objects and work pieces such as forgings comprising:

providing two image producing sensors, each being up and down tiltable about a horizontal axis, and swivable from side to side about a vertical axis and spacing them to have a particular distance between them;

directing at least one of the sensors towards the object for acquiring position data on a particular point of the object;

detecting in an image of the object, as produced by one sensor that is directed towards the object, contrasting lines and a particular point, being a point of intersection of two of the contrasting lines as detected;

positioning the one sensor, including tilting and swiveling respectively about two particular axes to have a particular image field point coincide with that particular point of intersection as imaged;

positioning the other sensor through tilting and swiveling about two particular axes to have a particular image field point of this other sensor trained on that same particular point of intersection; and

deriving dimensional and gauge data of the object from angular position data of the two sensors, by repeating the directing, detecting and positioning steps in relation to other points of intersection of contrast lines of the image of the object.

2. Method as in claim 1, including the step of optically marking said particular point following acquisition by the one sensor.

3. Method as in claim 1 including the step of prepositioning the sensors in relation to the object towards contrasting lines.

4. Method as in claim 1 and including using contrast enhancement of images as produced by the sensors.

5. Method as in claim 1, wherein the swiveling and tilting being carried out by means of motors.

6. Method as in claim 1, including the step of additionally marking particular additional points, not being defined by intersections of contrast lines, through spot illumination onto a surface of the object.

7. Method as in claim 1, including in addition the step of controlling a machine tool to copy the object whose dimensional and gauge data have been acquired.