Apparatus and method for estimation of initial phase of a brushless motor

摘要

An apparatus comprises a brushless motor, driver, incremental displacement sensor, and processor. The motor has a rotor, stator, and electrical terminals accepting a drive signal. The initial phase of the rotor is unknown. The driver is connected to the electrical terminals and produces the drive signal. The displacement sensor is configured to measure a displacement of the rotor and to produce an output signal. The processor has an input receiving the output signal and an output connected to the driver. The processor causes the driver to produce the drive signal according to a predetermined function of time, observes the output signal from the displacement sensor resulting from the drive signal, and performs mathematical computations on the basis of the observed output signal and a model of dynamic behavior of the motor to estimate the initial phase of the rotor.