An Improved Position Detection Method for Permanent Magnet Linear Motor Using Linear Hall Sensors

Two linear hall sensors are utilized to detect the mover position of permanent magnet linear motor (PMLM) in this paper. To eliminate the harmonics of the sensor signals, suboptimal multiple fading Kalman filter (SMFEKF) is utilized to estimate the mover position. The third-order harmonic is considered into the observation model of SMFEKF, and high-order harmonics are considered as measurement noise. Compared with traditional EKF, SMFEKF shows higher robustness against model parameter mismatch. Experimental results show that the proposed method can completely eliminate the impact of harmonics when the motor is stationary and significantly improve the accuracy when the motor is running.