Frames

Frames are what allow us to use mathematical expressions to define motion and positions in the real world.

Coordinate Systems

Joint

Joint Coordinate System - Each joint has a value based on degrees from a designated zero position.

The joint coordinate system

Cartesian

These are the three translational axis directions. On our robots, the positive X direction is toward the user standing in front of the robot.

In the bridge between computation and the physical world, we have to have some sort of reference to begin our measurements. Each point in space can be represented by three values represented by the characters X, Y, and Z. This is known as a "Cartesian" coordinate system.

To use a Cartesian system we have to define where 0 is for each axis. Since it does not affect the calculations and only makes it easier to understand, we define 0 as the same point for all 3.

The familiar looking image on the left demonstrates this. The intersection between the three axis lines is the "Zero" point.

There are three more axes to consider, but don't define the object's location in space. They are represented by the characters W, P, and R, colloquially referred to as yaW, Pitch, and Roll.

Yaw, Pitch, and Roll determine the object's orientation about the position defined in X, Y, and Z.

Yaw is the rotation about the X axis.

Pitch is the rotation about the Y axis.

Roll is rotation about the Z axis.

Frames

Jog Frame

This is the Tool Frame page on the Teach Pendant

This is the User Frame page on the Teach Pendant