doc-helmut wrote:I find it strange that you are unable to increase the distance
aswin, actually I'm curious why you're asking this, do you suppose me to be not sure about my own requirements?
No, that is not the reason. I thought you had to do this in a confined space.
But as I understand it you want to align a grabber more or less exactly with an object to be able to pick it up. You might be able to align your grabber much better than the resolution of your sensor! Let me try to explain. Suppose your sensor has a no detection angle. The goal is to find the center of an object. (we assume the object is square, this makes it easy to define he center.) the way to do this is to detect both the left and the right edge of the object. If you take the mean of these two you get the center. Now suppose the sensor is not perfect, it has a beam with some width. As a resulting detects the edge of an object a bit to soon. How much to soon is a function of distance and width of the beam. let say it is X. This means that the left edge is detected X too much to the left (-X), the right edges detected X too much to the right (+X). But if you take the average of the two to calculate the center you will see that the two X values cancel each other out. So, even when the sensor is not very precise you can still get precise measurements.
Hope this helps you.