Multiobjective Layered Optimization Analysis of Noncontact Integrated Permanent Magnet Vernier Motor for Deep-Sea Joint Motor

This paper proposes a non-contact integrated permanent magnet vernier motor (NCIPMVM) to address the challenges of implementing a high-performance direct-drive actuator within the extremely constrained and pressure-sealed environment of deep-sea joint motors. The core concept involves forming an axially rigid structure with a common inner rotor through the integration of a vernier motor and a magnetic gear (MG). To improve the effectiveness of the integrated design, an optimized layering strategy is introduced, which considers the demagnetization characteristics of permanent magnets (PMs). Sensitivity analysis and hierarchical parameter optimization are conducted using cross-parameter analysis in combination with the Pearson correlation coefficient. Design of experiment (DOE) models are then established across different levels, while NSGA-III and PSO algorithms are employed to perform parameter optimization. Layered optimization is further refined through iterative conditional constraints, with the goal of satisfying output performance requirements. Based on the optimized parameters, a prototype is fabricated. Finally, the validity and accuracy of both the proposed NCIPMVM and the optimization strategy are verified through finite element analysis (FEA) and experimental testing.