src/main/flight/gyroanalyse.h

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #pragma once
  22
  23 #ifdef USE_DYNAMIC_FILTERS
  24
  25 #include "arm_math.h"
  26 #include "common/filter.h"
  27
  28 /*
  29  * Current code works only with 64 window size. Changing it do a different size would require
  30  * adapting the gyroDataAnalyseUpdate in STEP_ARM_CFFT_F32 step
  31  */
  32 #define FFT_WINDOW_SIZE 64
  33
  34 typedef struct peak_s {
  35     int bin;
  36     float value;
  37 } peak_t;
  38
  39 typedef struct gyroAnalyseState_s {
  40     // accumulator for oversampled data => no aliasing and less noise
  41     float currentSample[XYZ_AXIS_COUNT];
  42
  43     // downsampled gyro data circular buffer for frequency analysis
  44     uint8_t circularBufferIdx;
  45     float downsampledGyroData[XYZ_AXIS_COUNT][FFT_WINDOW_SIZE];
  46
  47     // update state machine step information
  48     uint8_t updateStep;
  49     uint8_t updateAxis;
  50
  51     arm_rfft_fast_instance_f32 fftInstance;
  52     float fftData[FFT_WINDOW_SIZE];
  53     float rfftData[FFT_WINDOW_SIZE];
  54
  55     pt1Filter_t detectedFrequencyFilter[XYZ_AXIS_COUNT][DYN_NOTCH_PEAK_COUNT];
  56     float centerFrequency[XYZ_AXIS_COUNT][DYN_NOTCH_PEAK_COUNT];
  57
  58     peak_t peaks[DYN_NOTCH_PEAK_COUNT];
  59
  60     bool filterUpdateExecute;
  61     uint8_t filterUpdateAxis;
  62     uint16_t filterUpdateFrequency;
  63
  64     uint16_t fftSamplingRateHz;
  65     uint8_t fftStartBin;
  66     float fftResolution;
  67     uint16_t minFrequency;
  68     uint16_t maxFrequency;
  69
  70     // Hanning window, see https://en.wikipedia.org/wiki/Window_function#Hann_.28Hanning.29_window
  71     float hanningWindow[FFT_WINDOW_SIZE];
  72 } gyroAnalyseState_t;
  73
  74 STATIC_ASSERT(FFT_WINDOW_SIZE <= (uint8_t) -1, window_size_greater_than_underlying_type);
  75
  76 void gyroDataAnalyseStateInit(
  77     gyroAnalyseState_t *state,
  78     uint16_t minFrequency,
  79     uint32_t targetLooptimeUs
  80 );
  81 void gyroDataAnalysePush(gyroAnalyseState_t *gyroAnalyse, int axis, float sample);
  82 void gyroDataAnalyse(gyroAnalyseState_t *gyroAnalyse);
  83 #endif