Baxter Robot Forward and Inverse Kinematics

Validation of the forward and inverse kinematics of the Baxter robotic arm. A custom GUI was created in MATLAB to vary the joint angle of the robot. For avoiding the infinite solution problem and kinematically redundant case, we will be setting one degree of freedom (Elbow roll E0) to zero all the time. Now the resultant Baxter arm is a 6 DOF robot arm.
According to Pieper’s solution, for an analytic Inverse Kinematic solution to exist, the robot must have a minimum of three consecutive frames with the same origin. But in the case of Baxter’s arm, the presence of the link offset 𝐿5≠0 does not allow the system to have more than two consecutive frames with the same origin. Therefore, in order to calculate the inverse kinematic solutions, the link length 𝐿5 is set to 0. The link length being the smallest link of all the other links considered, the final error in computing the joint angles will be relatively small.
Therefore, to calculate the analytic solution to Baxter’s arm, the joint 𝜃3 is locked to 0 and the link length 𝐿𝐿5 is assumed to be zero.