通过测量非导通相的反电势波形，运用KALMAN滤波器，估计出转子的位置-By measuring the non-conduction phase of the BEMF waveform, using KALMAN filter, the estimated rotor position

Abstract—This paper presents a new 12-step sensorless drive for brushless dcmotor based on back-electromotive force (back-EMF) differences, which are estimated the disturbance observer (DOB) structure. Availability of rotor position information