Coordinate Frame and Joint Axes

Reference Frame

The reference frame of the robot is in the center between the fingers on the ground. The first finger (“finger0”) is aligned with the y-axis, the other two are rotated by 120° and 240° around the z-axes:

TriFingerPro model with a visualization of the world reference frame.

Joint Axes

Image of a FingerPro model with annotations of the joints rotation axes.

For “FingerPro” and “FingerEdu” fingers, directions of rotation (i.e. which direction is positive and which is negative) is as depicted in the image above.

For “FingerOne”, joint 1 is inverted, the others are the same.

Zero Position

All joints are in zero-position when the finger is pointing straight down:

Image of a FingerPro model with the finger tip pointing straight down.