No abstract

The establishment of the analytical model of the rotor eccentric surface-mounted permanent magnet synchronous motor (SPMSM) with unequal magnetic poles structure will be beneficial to calculating the magnetic field and studying noise characteristics quickly. Based on the equivalent surface current (ESC) method and equivalent boundary method, the analytical model of the rotor eccentric SPMSM with unequal magnetic poles structure is proposed. During the modeling process, the magnetic field produced by a permanent magnet (PM) is obtained using the ESC method, and the effect on the air gap magnetic field, which arised from stator, is replaced with the concentric current sheet (CCS) magnetic field. And, the analytical results of the magnetic field are confirmed by FEM. According to the analytical model of the SPMSM, the effect on the noise characteristics, which resulted from rotor eccentricity, is researched. Moreover, the experiments of noise comparison are done. The results validate the validity of noise characteristic research. Then, the analytical model of the SPMSM is further verified.

This paper presents the development of an upper limb end-effector based rehabilitation device for stroke patients, offering assistance or resistance along any 2-dimensional trajectory during physical therapy. It employs a non-backdrivable ball-screw-driven mechanism for enhanced control accuracy. The control system features three novel algorithms: First, the Implicit Euler velocity control algorithm (IEVC) highlighted for its stateof-the-art accuracy, stability, efficiency and generalizability in motion restriction control. Second, an Admittance Virtual Dynamics simulation algorithm that achieves a smooth and natural human interaction with the non-backdrivable end-effector. Third, a generalized impedance force calculation algorithm allowing efficient impedance control on any trajectory or area boundary. Experimental validation demonstrated the system's effectiveness in accurate end-effector position control across various trajectories and configurations. The proposed upper limb endeffector-based rehabilitation device, with its high performance and adaptability, holds significant promise for extensive clinical application, potentially improving rehabilitation outcomes for stroke patients.

No abstract