FFT sliding window #20296
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FFT sliding window #20296
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Could you describe how you perform the testing in sitl for this one? Once i get a chance to look at more I might see about testing it on a large vehicle soon. |
tridge
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May 25, 2022
allow configuration of DSP averaging frames via FFT_NUM_FRAMES
calculate frequency average from sliding window
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Added SITL checks and ran on a KakuteH7Mini with --malloc-guard-enabled - all good @hendjoshsr71 the PR includes a test to run in SITL - fly.ArduCopter.GyroFFTContinuousAveraging |
tridge
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Jun 1, 2022
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This PR uses continuous averaging of FFT frames reducing noise in the analysis. Welch's method of FFT averaging requires that the input be stationary, so it is not possible to average very many frames without biasing the data. That said some amount of averaging can help especially in situations where signals may be moving more slowly (e.g. larger copters). The behaviour is enabled by setting:
where x is the number of frames to average over. In SITL on a noisy test the results are, before:
after:
it's hard to see the difference, but the test using averaging always completes after one attempt, whereas the non-averaging test takes several attempts to complete
Flew this on my Y6B with FFT_NUM_FRAMES = 5
Before:
After:
The difference is pretty dramatic in terms of noise reduction