Magnetic Equivalent Circuit Model for Performance Prediction of Two-DOF Planar Resolver

Abstract

In this paper, an analytical model based on the Magnetic Equivalent Circuit (MEC) method is developed for a planar wound mover two-degree of freedom (2-DOF) resolver. Planar resolvers enable mass, volume, and complexity reductions for position control of 2-DOF linear actuators. However, similar to any other linear electromagnetic sensors, the performance of the planar resolvers is negatively affected by the limited dimensions of the mover’s ferromagnetic core. Thus, it is necessary to develop an appropriate compensation method. On the other hand, the 3-D geometry of the sensor necessitates extremely time consuming 3-D time-stepping analysis. Therefore, a fast yet accurate analytical model is critical for the iterative design and compensation algorithm. In order to address these modeling limitations, the slot-tooth region and longitudinal end effect are included in the model. Then, its accuracy is verified by comparing the results with those of the 3-D time stepping finite element method (TSFEM). Then, the developed model is employed for design optimization to compensate for the end effects. Finally, the optimal sensor is experimentally prototyped and tested.

Keywords

• Two-DOF resolver
• linear resolver
• wound mover resolver
• longitudinal end effect
• magnetic equivalent circuit (MEC)