Electricity: motive power systems – Positional servo systems – Program- or pattern-controlled systems
Patent
1992-06-18
1993-09-21
Shoop, Jr., William M.
Electricity: motive power systems
Positional servo systems
Program- or pattern-controlled systems
318577, 318640, 36447403, 36447405, G05B 1933
Patent
active
052472337
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
1. Technical Field
This invention relates to a non-contact digitizing control device, and more particularly, to a digitizing control device for a non-contact tracing of a model surface to thereby generate tracing data related to a model shape.
2. Background Art
Tracing control devices using an optical distance detector for obtaining data related to a model shape by a non-contact tracing procedure have been developed for use in place of tracing devices having the function of tracing a model by placing a stylus in contact with the model, and at the same time, machining a workpiece to the same shape as the model. Further, if an NC device is given a tracing function, tracing data related to a model shape can be generated without directly combining the NC device with the tracing control device.
Generally, a device capable of tracing a model surface to obtain time-based tracing data, and automatically outputting the obtained data to an NC tape or the like, is called a digitizing control device.
Non-contact digitizing control devices can provide tracing data without the need for pressing a detector against a model surface, and accordingly, digitizing data can be calculated from information about the displacement of a tracer head when carrying out a non-contact tracing of the model surface, without damaging the model surface. The optical distance detectors conventionally employed for this purpose are a spot type wherein a spot light is irradiated onto a model surface and the distance from the model surface to a light-receiving face of the detector is detected.
In such spot type distance detectors, the tracer head must be controlled with reference to the model surface in such a manner that the light-receiving face of the detector is oriented in an optimum direction, because the accuracy of the detection of the distance from the model to the detector affects the digitizing data.
The distance detector is fixed to the tracer head, and usually follows the model surface at a location spaced therefrom by a reference distance. Accordingly, where the inclination of the model surface is small, an error in the distance detection poses nc significant problem, but where the angle of inclination of the model surface is large, the angle between the tracer head and the normal line of the model surface also becomes large, and accordingly, the distance from the model surface becomes greatly deviated from the reference distance. As a result, the accuracy in detecting the distance from the model to the detector is lowered, an interference with the model surface occurs, and the tracing accuracy is adversely affected.
Accordingly, the inventors filed a patent application (Japanese Patent Application No. 1-194500) entitled "Non-contact Tracing Control Device" for an invention wherein the normal line of a model surface is derived from data related to the model shape and the rotation of the tracer head is controlled in accordance with variations in the direction of the normal line.
Nevertheless, where the model surface is nearly horizontal, the orientation of the tracer head, the rotary motion of which is controlled, becomes unstable due to an error in calculating the normal line or a measurement error.
DISCLOSURE OF THE INVENTION
This invention was created in view of the above circumstances, and an object thereof is to provide a digitizing control device capable of rotating and positioning a tracer head in a direction best following the inclination of a model surface, to thereby permit a stable non-contact tracing operation.
To achieve the above object, this invention provides a digitizing control device for generating tracing data related to a shape of a model while a tracer head carries out a non-contact tracing of the model shape, which comprises control means for controlling a control axis to thereby position the tracer head in a direction perpendicular to a surface on which the model is placed, and a rotary axis which controls a rotation of the tracer head around the control axis while the tracer head is inclined
REFERENCES:
patent: 4651283 (1987-03-01), Sciaky et al.
patent: 4905158 (1990-02-01), Seki et al.
patent: 4905315 (1990-02-01), Solari et al.
patent: 5019993 (1991-05-01), Montaleini et al.
patent: 5140239 (1992-08-01), Matsuura
Matsumoto Eiji
Matsuura Hitoshi
Fanuc Ltd
Shoop Jr. William M.
Sircus Brian
LandOfFree
Digitizing control device for generating tracing data does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Digitizing control device for generating tracing data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digitizing control device for generating tracing data will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1052912