I read a noisy signal from an accelerometer which is attached to the pedal of a stationary bike and need to find the frequency of the signal/ speed of the person cycling. I taught of the following solutions and would like to know if I overlooked any or made some incorrect assumptions.
Currently the working solution is a low pass (10-30 point moving average) and then a peak detection with a minimum amplitude requirement and minimum time requirement. However this solution doesn't work very well when nearing 0.33Hz (20 RPM)
I tried using an fft but the result was never accurate enough for the small differences in frequency I am looking for.
I taught about using autocorrelation but how I understand it, I would have to wait atleast a period and then some before I could detect the frequency.
Any other ideas are welcome, or if anybody knows what is used in the commercial version it would be great to know.