How to understand the orientation of an electrolytic capacitor on a pcb board.

[FM82]

Good day to all. I must develop an application that check the orientation (+ and -) of an electrolytic capacitor. I tryed with pattern matching but the results are poor. I need some hint on how to proceed.

Thank you in advance, Francesco.

[Klemen]

Hello,

can you perhaps share an image of the capacitor? Are they the same on all PCB's?

Is it positioned cathode up or down? How good is the PCB positioning repeatability? Does it rotate, scale, etc... (is it machine guided or do you place it manually)? Is the camera fixed? Are there significant illumination changes?

The first step is to introduce some constraints. Your question is very loose.  No algorithm will perform roboustly in very different conditions (up to some extent, yes).

Leaving all above aside, my advice is to first roughly localize the part (determine the region of interest) and then perform refined detection/classification of your part (or features on your part).

Best reagards,

K

[FM82]

I haven't, at this time, the pcb board so i try to understand what to do first. I think that i can consider the pcb position fixed and same for the ROIs. The capacitor may be of different type so i need to make a software that can run anywhere, maybe after the definition of a new template and new ROIs.