The Design of Decoupled Robotic Arm Based on Chain Transmission

Abstract

Unlike the conventional robotic arm where the joints are coupled to each other, this paper proposes a position and posture decoupling method to mechanically correct the end position of the robotic arm in real time through dual-motion transmission, which is both motor-reducer-driven and chain-driven; when the position of the end of the robotic arm changes, the positional linkage of each articulated arm end is unaffected. First, a single-section chain-driven decoupled robotic arm is constructed, and then the design of a two-degrees-of-freedom chain-driven decoupled robotic arm system is completed based on a single arm. Second, kinematic analysis of the decoupled robotic arm system is performed to obtain its trajectory and workspace. Moreover, an analysis of the transmission mechanism engagement clearance error is carried out. Finally, a mini-experimental prototype is built, and the rationality of the decoupled robotic arm system is proven by experiments. The experimental results show that the robotic arm is generally able to realize positional decoupling stably during movement, providing certain theoretical support and practical experience for the design requirements of related robotic arms.