| 摘要 |
<p>The method involves detecting an electrical signal i.e. motor current signal (Imotor), of a permanently excited direct current motor. The electrical signal is filtered using an adaptive filter device (1), and a filtered electrical signal is generated. A ripple of the filtered electrical signal is detected. An actual frequency of the ripple is determined. An instantaneous frequency of the ripple is calculated. An expected frequency value is calculated from the actual frequency of the ripple, the instantaneous frequency of the ripple and a weighting factor, during an initial phase of the motor.</p> |
