摘要：针对直流电机无转速传感器间接测速问题，构造了基于局部特征尺度分解的具有自适应能力的滤波器组；依据直流电机电枢电流中噪声频率高、幅值小和换向电流频率高、幅值大这一特性，确定了滤波器组中内禀模态分量（Intrinsic Scale Component ，ISC）分量的阶数以组成换向电流；为避免复杂换向过程引起的换向电流频率突变，提出了基于中心极值差分（Central Extreme Difference，CED）的换向电流频率求取方法；最后，根据电机电流频率和转速间的关系，获取了电机的转速特性。实验结果表明所提方法提取的换向电流较平滑，不仅获取的转速曲线波动程度较小、不存在转速突变，而且计算速度也有大幅度的提高。

关键词：直流电机；换向电流；特征尺度分解；内禀尺度分量；自适应滤波；中心极值差分

Abstract: Focusing on the DC motor speed sensorless indirect measurement, filter with adaptive ability based on LCD was bulid On the basis of the characteristics of DC motor armature current noise in high frequency, small amplitude and high frequency, large amplitude commutation current, order of ISC component filter group consisting of commutation current was determined In order to avoid commutating current frequency of mutation caused by complex commutation process, this paper proposed a method of getting commutating current frequency based on center extreme difference (Central Extreme Difference, CED)Finally, according to the relationship between the motor current frequency and speed, the speed characteristics of the motor was got The experimental results show that the proposed method for extraction of commutation current is smooth, not only the speed curve fluctuations smaller, there is no speed mutation, and the computation speed is greatly improved

Key words: DC motor; commutation current; local characteristic decomposition; intrinsic scale component; adaptive filtering; central extreme difference