Position estimation and error analysis in linear switched reluctance motors

In this paper, a continuous position estimation scheme is presented for linear switched reluctance motors (LSRMs). The scheme uses diagnostic current injection into an unenergized phase to detect the motor position. This paper proposed that a new current integration index be used to quantify the measurement of current waveform. Hardware implementation results demonstrate the effectiveness of the proposed estimation scheme for the LSRM. This paper also performs a study on the accuracy of the estimated position. Through the detailed experimental data, the approach of polynomial fitting is compared with the lookup table with regard to characteristic curve representation. The estimation error distributions and their standard deviation show that the accuracy and precision are close between these two approaches.