Hybrid Optimization and Comparative Analysis of a Novel Double-Side Asynchronous Rotor Axial-Flux Permanent Magnet Machine

Robot dogs are a new kind of transportation applied in express delivery and community patrol. The special structure makes them require high torque density and compact actuators. Then, a novel double-side asynchronous rotor axial-flux permanent magnet (DSAR-AFPM) machine is proposed for robot dogs. The 24-slot-20-pole (24S20P) and 36S42P configurations are adopted on two sides of the DSAR-AFPM machine. In addition, the winding configurations on the two sides are also different. The two sides are isolated by the stator yoke to ensure independent operation. Thus, the proposed DSAR-AFPM machine can drive the lower leg and thigh simultaneously. Then, a hybrid optimization is proposed in this article to optimize the DSAR-AFPM machine. It combines the quasi-3-D finite-element method and 3-D parametric analysis. The hybrid optimization greatly reduces the computational burden and increases the accuracy. In addition, a comparative analysis is conducted for the DSAR-AFPM machine. The comparison is performed between the DSAR-AFPM machine and two single-side counterparts AFPM machines. The independent operation of the two sides is verified. Finally, an experiment is performed to validate the performance of the DSAR-AFPM machine.