Centering a reference pattern under a camera through the movimentation of two axis

[FM82]

Hello again, i have some doubts that i hope you can help dissipate.

I need to develop an algorithm capable of centering a reference pattern under a camera (by the way, i have the Vision Library). To centering the pattern i can control two motor that move two axis (x and y); the message that i can send to the motor permit me to control the distance that a single motor can travel in a single shot (distance and velocity, it's simplified G Code).
The better solution is to calibrate the system and transform pixel's coordinates in mm's coordinates and then program the motors to travel the right distances. But what if i can't go this way? I've been thinking on PID controller but i'm not sure if i can make it works in this case.

Any help would be appreciated, thank you very much.

Francesco.

[Dagaror]

Hi Francesco,

I don't know if you still are in trouble. 

I think the better solution is to calibrate the image with a grid and later you will acquire the x and y axis position in millimeter. Later you pass the information to the driver which controls both motors and you can elaborate a PID or whatever the driver allows you.

https://www.ni.com/docs/en-US/bundle/ni-vision-concepts-help/page/geometric_matching_using_calibrate...

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019LXhSAM&l=en-US

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P8pXSAS&l=en-US

https://forums.ni.com/t5/Example-Code/Archived-Download-NI-com-Obsolete-NI-Vision-Web-Examples/ta-p/...

https://www.youtube.com/watch?v=rv_3bUnS1pE

https://www.youtube.com/watch?v=eWqq65ZZ0NQ

Good luck and enjoy!

[FM82]

Thank you Daragor. I've managed to do it in another way but i think that the links that you give me are still useful so: thank you again!!