Low-cost position sensing technique for Linear Switch Reluctance Motion system

Abstract

This paper presents a novel position sensing system for a linear switched reluctance motor. By measuring the magnetic flux differences on the fixed tooth track using two coiled devices aligned 90 degrees out of phase, the position and direction information of the moving platform can be obtained. To increase the resolution 16 times its original tooth pitch, a novel non-sinusoidal waveform interpolation technique is employed. The proposed sensing system is designed, fabricated and implemented on a linear variable reluctance motor platform. Results show that the proposed sensing system can produce reliable position information with high accuracy and repeatability, and at high pulse output rate. The proposed position measurement method is useful for both phase commutation and servo position feedback of the Linear Switched Reluctance Motor.