Design of A New Double Side Axial-Flux Actuator for Robot Dog

A novel double side axial-flux actuator (DSAFA) is proposed to reduce the volume of the actuator system for robot dogs. It is an axial-flux permanent magnet (AFPM) machine with two rotors and one stator. The pole-slot combinations on two sides of the DSAFA are 24-slot-20-pole and 36-slot-42-pole configurations. They can work independently so that the DSAFA can control the thigh and lower legs at the same time. A quasi-3D finite element method (FEM) is used to analyze the parameters of the DSAFA. Then, a 3D FEM is applied to conduct a parametric study and optimize the geometry. The average torques of the optimal structure are 4.14 Nm and 3.96 Nm, while the torque ripples are reduced to be 0.23 Nm and 0.03 Nm. Finally, the DSAFA shows the same performances when compared with two single-side benchmark AFPM machines.