Mechanism Development and Pulse-Width Modulation Advanced Controller Design of Low Torque Manipulator

In most conventional robotic arms, the motors are installed on the rotating shafts within the arm, which means that the shape and size of the motors must be considered in the design of the arm, while the weight of the motors increases the torque on the supporting joints generated during arm movements. This paper presents a dual-axis robotic arm with the motors installed on the base of the device to overcome these issues. Movement around the first axis is driven by a gear, while that of the second axis is driven by a belt. Trajectory tracking is controlled by an adaptive sliding mode controller (ASMC). In simulations and experiments, the proposed robotic arm outperformed arms using PID control and sliding mode control (SMC) in terms of tracking accuracy and stability.