Trajectory Control of a 4-Degree-Of-Freedom Digital Twin Robotic Arm Using a Fuzzy Controller and an Adaptive PID Controller

Abstract

Trajectory control of robotic manipulators plays a central role in modern automation systems, where precise, smooth, and responsive motion is essential for achieving task success. In industrial environments, robotic arms must follow complex paths to exe cute operations such as welding, assembly, pick-and-place, and component inspection. The difficulty lies in ensuring that these motions are not only accurate and repeatable but also dynamically feasible under the constraints of each robot’s kinematics and me chanical structure. Controlling a robotic arm with multiple degrees of freedom (DOF), such as a 4-DOF system, introduces additional challenges. The control system must account for non linear dynamics, joint coupling effects, actuation limits, and uncertainties in both the model and the operating environment. In addition, trajectory generation must be op timized to reduce energy consumption, avoid singularities, and maintain real-time re sponsiveness, especially in industrial contexts where delays and inaccuracies directly translate into economic losses or operational risks.