Matching Design and Multi-objective Optimization of Integarated joint for collaborative robot

Driving joints are the core components of collaborative robots, but existing joints have low torque density and poor dynamic response performance. This article proposes a novel integrated joint composed of a hollow AFPM motor and an embedded planetary gear reducer, which enhance the output performance, i.e., high torque density and efficiency, high dynamic response. Aiming at achieving the superior performance, a matching-oriented design method is proposed for the integrated joint. This design method reveals the impacts mechanisms between the structural parameters (including AFPM motor and planetary reducer) and the output performance. The multi-objective optimization is conducted to obtain the optimal design parameters by using NSGA-II. The optimized design is compared with the initial one, which indicates that the weight of the optimized joint is reduced by 49g, the joint torque density is increased by 36.8%, and the dynamic response performance is improved by 31.5%.