Comparison of Inverse Kinematics Approaches for 3-Joint 4-Link Robots in 2D Space

Nowadays, the real world widely uses robotic arms, leading to an increasing amount of research in this field. This work is mainly about the Inverse Kinematics about 3 joint 4 link robots in 2D space. The primary challenge lies in calculating joint angles using known final coordinates. This research will present two distinct approaches, each capable of resolving the problem. By using cosine function, the first way, geometrical, could solve the problem in 2-D space. Despite appearing more challenging than the first method, the algebraic approach, the second method, can solve the problem in both 2-D and 3-D space by modifying the size of the rotation matrix, also known as the DH matrix. Due to geometric limitations, error analysis will be presented exclusively when employing algebraic methods. We calculate the derivative on the axis to depict the changing trend. Meanwhile, further study is also provided.