u/Friendlygrandma

ORI1 and ORI2 velocity in KUKA KR6

Hello everyone,

I am currently developing my thesis using a KUKA KR6 robotic manipulator. The purpose is to use it to test new and upcoming knee surgeries on cadaveric knees. The femur will be fixed to a table, and the manipulator will move the tibia in relation to it. I have programmed the trajectories in KRL, using LIN movements. I am now on to the part of programming the correct anatomical velocities.

The knee has 6 degrees of freedom, which correspond directly to Cartesian coordinates in my Kuka setup as follows:

X - Anterior Drawer

Y - Lateral Shift

Z - Joint Distraction

A - External Rotation

B - Flexion

C - Abduction

I have data on the angular velocity of knee flexion, and I want to translate it into information I can input into my KRL program. However, Kuka only takes VEL.CP, VEL.ORI1 and VEL.ORI2.

If I'm understanding correctly, VEL.ORI1 is the velocity of the Z axis turning on itself, so it's directly the External rotation velocity. However, I am not clear on what the ORI2 velocity is. I have seen on other online forums that it is the velocity of the angle phi, in spherical coordinates (https://en.wikipedia.org/wiki/File:3D\_Spherical\_2.svg), is that correct?

Additionally, does anyone have an insight on how I could translate the angular velocity of the flexion (B), into these velocity components?

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u/Friendlygrandma — 2 days ago