Dynamics and Control of a Robotic Arm Having Four Links

The manipulator control is an important problem in robotics. To work out this problem, a correct dynamic model for the robot manipulator must be in hand. Hence, this work first presents the dynamic model of an existing 4-DOF robot manipulator based on the Euler–Lagrange principle, utilizing the body Jacobian of each link and the generalized inertia matrix. Furthermore, essential properties of the dynamic model are analyzed for the purpose of control. Then, a PID controller is designed to control the position of the robot by decoupling the dynamic model. To achieve a good performance, the differential evolution algorithm is used for the selection of parameters of the PID controller. Feedback linearization scheme is also utilized for the position and trajectory tracking control of the manipulator. The obtained results reveal that the PID control coupled with the differential evolution algorithm and the feedback linearization control enhance the performance of the robotic manipulator. It is also found out that increasing masses of manipulator links do not affect the performance of the PID position control, but higher control torques are required in these cases.