DC Motor Speed Calculation Based on Armature Current Measurement

DC motor speed can be indirectly obtained by measuring armature current. As for steady armature current, period estimation method in time domain and spectrogram method in frequency domain have both been adopted to calculate DC motor speed, and experiment results indicate that the spectrogram method has better accuracy. As for starting armature current, the current can be de-noised by the method of wavelet packet floating threshold, its high frequency component can be extracted by a high pass filter, and DC motor speed can be calculated by wavelet analysis with high effectiveness and accuracy proven by the results.