Baxter has seven rotary joints as shown in the following figure. Each arm is often referred to as a 7-DOF arm, since motion of the arm is controlled by seven actuators (motors) that are capable of independent rotation.
Baxter's 7-DOF arms are described on the Rethink Robotics site at http://sdk.rethinkrobotics.com/wiki/Arms.
The arm joints are named in the following manner:
The designation of the joints as S0, S1, E0, E1, W0, W1, and W2 enables us to define and even monitor each of the angles for these joints with ...