# Calculate Roll, Pitch, Yaw from a normal vector

Hello everyone,
I have a Fanuc Robot ARC MATE 100ic.I have a normal vector N= (0.963665164640684, 1.27688742042028E-09, 0.267113179117099). My questions is, how can I calculate the angle of Roll, Pitch, Yaw from this normal vector.
Appreciate any help and suggestion.
Thanks and Best regards,
Lam Nguyen

I’m not a Fanuc expert, but geometrically speaking you cannot do that, as there is no “roll” around a vector. To get those you would need to represent your robot position with a plane, as we do with KUKA|prc.
That being said, there is of course the possibility that the Fanuc can simply “lock” that degree of freedom, so that you only need two angles, which you can get from a vector.
Best,
Johannes

Does this help?

– Dale

Hello Johannes,
you are right, I have the orientation of end effector P = [0,0,-1]. Therefore, N=Rxyz.P, SinB= -Nx, SinACosB=Ny, CosACosB=Nz. apparently, there is no “roll”.

Thanks
Lam

Hello Dale,
I have tried, but it does not help.
Thanks
Lam

hello Lam
I met problem similar yours. I also want calculate roll, pitch, yaw from normal vector but i find any way to do. Can i help me or give me some key word and instructions about this problem.
Thanks