问题
I've noticed in Apple's accelerometer sample code they use both regular and adaptive low pass filters, what is the difference?
回答1:
They are both IIR 1st order low pass filters (simple, and laggy in responsiveness when compared with other DSP techniques). The adaptive filter switches to a higher frequency roll-off (and thus becomes even less smoothing but more responsive) for larger accelerations.
There are other higher quality (and more complicated) DSP filtering techniques for motion sensing often used by portable game developers.
回答2:
In general, any adaptive filter will adjust itself based on the input signal. I'm not sure if you'll notice much difference in practice. Just try it out and see if one gives better response to what you're trying to do.
回答3:
IIR Adaptive has a flatter response curve which means you have a higher fidelity output. Or, in other words, what you put in is what you get out.
来源：https://stackoverflow.com/questions/4272259/what-is-the-difference-between-a-regular-and-adaptive-low-pass-filter