Scale

Set a scale search.

<1> Ignore scale in the search
<2> Do a scale search within the range specified by the upper and lower limits

For example, suppose that you teach the geometry shown in Fig.(i) and that the image captured by the camera shows the workpiece having the same geometry but expanded by 3%.

If you specify <1>, scale is ignored in the search. The tool pays attention only to the scale specified by the [Nom.] and finds those patterns that are not expanded like the one shown in Fig.(ii). Any deviation in scale is regarded as geometrical distortion, and the score is reduced as much.

If you specify <2>, a scale search is done within the range specified by the [Min.] and [Max.] limits. Therefore, a pattern like the one shown in Fig.(iii) can also be found as a fully matching pattern.

In the case of <3>, care must be taken because a pattern is not found if its scale is outside the range specified by the [Min.] and [Max.] limits, regardless of how slightly.

The time the location process takes is shorter in the case of <1> than <2>. If you specify <2>, the location process takes less time when the scale range is narrower.

(i) Model pattern
(ii) Reference scale 100%
(iii) Scale range±10%
Fig. :Scale range
Scale A change in the scale, or a change in the size of the figure in the image captured by the camera, means that "the distance between the camera and the workpiece has changed". As described with relation to parallax, if the distance between the camera and the workpiece changes, the actual travel amount of the object becomes different even if the apparent travel amount in the image remains unchanged. Therefore, a change in the distance between the camera and the workpiece makes the tool unable to calculate the actual travel amount of the object correctly from the travel amount of the object in the image. This can impede the accurate offset of the robot position.If the apparent scale has changed even though the distance between the camera and the workpiece has not changed, you might have altered the lens zoom or focus. In this case, by letting the GPM Locator Tool do a scale search as well, you can have the location process itself accomplished. Doing so, however, makes the tool unable to calculate the actual travel amount of the object correctly from the travel amount of the object in the image, thereby impeding the accurate offset of the robot position.When using the scale search, make sure that not only the GPM Locator Tool but also the entire application, including robot position offset, are prepared for cases when patterns having different scales are found.