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Added tracking of multiple dynamic notches per axis and replaced FFT with SDFT

This commit is contained in:
KarateBrot 2020-09-22 18:15:06 +02:00
parent 7b46440056
commit d02af7334c
16 changed files with 504 additions and 326 deletions
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11
make/source.mk
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@ -226,6 +226,7 @@ SPEED_OPTIMISED_SRC := $(SPEED_OPTIMISED_SRC) \
common/encoding.c \ common/encoding.c \
common/filter.c \ common/filter.c \
common/maths.c \ common/maths.c \
common/sdft.c \
common/typeconversion.c \ common/typeconversion.c \
drivers/accgyro/accgyro_mpu.c \ drivers/accgyro/accgyro_mpu.c \
drivers/accgyro/accgyro_mpu3050.c \ drivers/accgyro/accgyro_mpu3050.c \
@ -397,16 +398,6 @@ ifneq ($(DSP_LIB),)
INCLUDE_DIRS += $(DSP_LIB)/Include INCLUDE_DIRS += $(DSP_LIB)/Include
SRC += $(DSP_LIB)/Source/BasicMathFunctions/arm_mult_f32.c
SRC += $(DSP_LIB)/Source/TransformFunctions/arm_rfft_fast_f32.c
SRC += $(DSP_LIB)/Source/TransformFunctions/arm_cfft_f32.c
SRC += $(DSP_LIB)/Source/TransformFunctions/arm_rfft_fast_init_f32.c
SRC += $(DSP_LIB)/Source/TransformFunctions/arm_cfft_radix8_f32.c
SRC += $(DSP_LIB)/Source/CommonTables/arm_common_tables.c
SRC += $(DSP_LIB)/Source/ComplexMathFunctions/arm_cmplx_mag_f32.c
SRC += $(DSP_LIB)/Source/StatisticsFunctions/arm_max_f32.c
SRC += $(wildcard $(DSP_LIB)/Source/*/*.S) SRC += $(wildcard $(DSP_LIB)/Source/*/*.S)
endif endif

4
src/main/blackbox/blackbox.c
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@ -1419,8 +1419,8 @@ static bool blackboxWriteSysinfo(void)
BLACKBOX_PRINT_HEADER_LINE("gyro_to_use", "%d", gyroConfig()->gyro_to_use); BLACKBOX_PRINT_HEADER_LINE("gyro_to_use", "%d", gyroConfig()->gyro_to_use);
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
BLACKBOX_PRINT_HEADER_LINE("dyn_notch_max_hz", "%d", gyroConfig()->dyn_notch_max_hz); BLACKBOX_PRINT_HEADER_LINE("dyn_notch_max_hz", "%d", gyroConfig()->dyn_notch_max_hz);
BLACKBOX_PRINT_HEADER_LINE("dyn_notch_width_percent", "%d", gyroConfig()->dyn_notch_width_percent); BLACKBOX_PRINT_HEADER_LINE("dyn_notch_count", "%d", gyroConfig()->dyn_notch_count);
BLACKBOX_PRINT_HEADER_LINE("dyn_notch_q", "%d", gyroConfig()->dyn_notch_q); BLACKBOX_PRINT_HEADER_LINE("dyn_notch_bandwidth_hz", "%d", gyroConfig()->dyn_notch_bandwidth_hz);
BLACKBOX_PRINT_HEADER_LINE("dyn_notch_min_hz", "%d", gyroConfig()->dyn_notch_min_hz); BLACKBOX_PRINT_HEADER_LINE("dyn_notch_min_hz", "%d", gyroConfig()->dyn_notch_min_hz);
#endif #endif
#ifdef USE_DSHOT_TELEMETRY #ifdef USE_DSHOT_TELEMETRY

4
src/main/cli/settings.c
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@ -679,8 +679,8 @@ const clivalue_t valueTable[] = {
{ "gyro_to_use", VAR_UINT8 | HARDWARE_VALUE | MODE_LOOKUP, .config.lookup = { TABLE_GYRO }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, gyro_to_use) }, { "gyro_to_use", VAR_UINT8 | HARDWARE_VALUE | MODE_LOOKUP, .config.lookup = { TABLE_GYRO }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, gyro_to_use) },
#endif #endif
#if defined(USE_GYRO_DATA_ANALYSE) #if defined(USE_GYRO_DATA_ANALYSE)
{ "dyn_notch_width_percent", VAR_UINT8 | MASTER_VALUE, .config.minmaxUnsigned = { 0, 20 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_width_percent) }, { "dyn_notch_count", VAR_UINT8 | MASTER_VALUE, .config.minmaxUnsigned = { 1, DYN_NOTCH_COUNT_MAX }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_count) },
{ "dyn_notch_q", VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { 1, 1000 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_q) }, { "dyn_notch_bandwidth_hz", VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { 1, 1000 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_bandwidth_hz) },
{ "dyn_notch_min_hz", VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { 60, 250 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_min_hz) }, { "dyn_notch_min_hz", VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { 60, 250 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_min_hz) },
{ "dyn_notch_max_hz", VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { 200, 1000 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_max_hz) }, { "dyn_notch_max_hz", VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { 200, 1000 }, PG_GYRO_CONFIG, offsetof(gyroConfig_t, dyn_notch_max_hz) },
#endif #endif

1
src/main/cms/cms_menu_firmware.c
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@ -25,6 +25,7 @@
#include <ctype.h> #include <ctype.h>
#include <stdbool.h> #include <stdbool.h>
#include <string.h>
#include "platform.h" #include "platform.h"

16
src/main/cms/cms_menu_imu.c
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@ -752,8 +752,8 @@ static CMS_Menu cmsx_menuFilterGlobal = {
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
static uint16_t dynFiltNotchMaxHz; static uint16_t dynFiltNotchMaxHz;
static uint8_t dynFiltWidthPercent; static uint8_t dynFiltCount;
static uint16_t dynFiltNotchQ; static uint16_t dynFiltBandwidthHz;
static uint16_t dynFiltNotchMinHz; static uint16_t dynFiltNotchMinHz;
#endif #endif
#ifdef USE_DYN_LPF #ifdef USE_DYN_LPF
@ -771,8 +771,8 @@ static const void *cmsx_menuDynFilt_onEnter(displayPort_t *pDisp)
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
dynFiltNotchMaxHz = gyroConfig()->dyn_notch_max_hz; dynFiltNotchMaxHz = gyroConfig()->dyn_notch_max_hz;
dynFiltWidthPercent = gyroConfig()->dyn_notch_width_percent; dynFiltCount = gyroConfig()->dyn_notch_count;
dynFiltNotchQ = gyroConfig()->dyn_notch_q; dynFiltBandwidthHz = gyroConfig()->dyn_notch_bandwidth_hz;
dynFiltNotchMinHz = gyroConfig()->dyn_notch_min_hz; dynFiltNotchMinHz = gyroConfig()->dyn_notch_min_hz;
#endif #endif
#ifdef USE_DYN_LPF #ifdef USE_DYN_LPF
@ -795,8 +795,8 @@ static const void *cmsx_menuDynFilt_onExit(displayPort_t *pDisp, const OSD_Entry
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
gyroConfigMutable()->dyn_notch_max_hz = dynFiltNotchMaxHz; gyroConfigMutable()->dyn_notch_max_hz = dynFiltNotchMaxHz;
gyroConfigMutable()->dyn_notch_width_percent = dynFiltWidthPercent; gyroConfigMutable()->dyn_notch_count = dynFiltCount;
gyroConfigMutable()->dyn_notch_q = dynFiltNotchQ; gyroConfigMutable()->dyn_notch_bandwidth_hz = dynFiltBandwidthHz;
gyroConfigMutable()->dyn_notch_min_hz = dynFiltNotchMinHz; gyroConfigMutable()->dyn_notch_min_hz = dynFiltNotchMinHz;
#endif #endif
#ifdef USE_DYN_LPF #ifdef USE_DYN_LPF
@ -817,8 +817,8 @@ static const OSD_Entry cmsx_menuDynFiltEntries[] =
{ "-- DYN FILT --", OME_Label, NULL, NULL, 0 }, { "-- DYN FILT --", OME_Label, NULL, NULL, 0 },
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
{ "NOTCH WIDTH %", OME_UINT8, NULL, &(OSD_UINT8_t) { &dynFiltWidthPercent, 0, 20, 1 }, 0 }, { "NOTCH COUNT", OME_UINT8, NULL, &(OSD_UINT8_t) { &dynFiltCount, 1, DYN_NOTCH_COUNT_MAX, 1 }, 0 },
{ "NOTCH Q", OME_UINT16, NULL, &(OSD_UINT16_t) { &dynFiltNotchQ, 0, 1000, 1 }, 0 }, { "NOTCH WIDTH HZ", OME_UINT16, NULL, &(OSD_UINT16_t) { &dynFiltBandwidthHz, 1, 1000, 1 }, 0 },
{ "NOTCH MIN HZ", OME_UINT16, NULL, &(OSD_UINT16_t) { &dynFiltNotchMinHz, 0, 1000, 1 }, 0 }, { "NOTCH MIN HZ", OME_UINT16, NULL, &(OSD_UINT16_t) { &dynFiltNotchMinHz, 0, 1000, 1 }, 0 },
{ "NOTCH MAX HZ", OME_UINT16, NULL, &(OSD_UINT16_t) { &dynFiltNotchMaxHz, 0, 1000, 1 }, 0 }, { "NOTCH MAX HZ", OME_UINT16, NULL, &(OSD_UINT16_t) { &dynFiltNotchMaxHz, 0, 1000, 1 }, 0 },
#endif #endif

6
src/main/common/filter.c
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@ -29,8 +29,6 @@
#include "common/maths.h" #include "common/maths.h"
#include "common/utils.h" #include "common/utils.h"
#define M_LN2_FLOAT 0.69314718055994530942f
#define M_PI_FLOAT 3.14159265358979323846f
#define BIQUAD_Q 1.0f / sqrtf(2.0f) /* quality factor - 2nd order butterworth*/ #define BIQUAD_Q 1.0f / sqrtf(2.0f) /* quality factor - 2nd order butterworth*/
// NULL filter // NULL filter
@ -46,7 +44,7 @@ FAST_CODE float nullFilterApply(filter_t *filter, float input)
float pt1FilterGain(float f_cut, float dT) float pt1FilterGain(float f_cut, float dT)
{ {
float RC = 1 / ( 2 * M_PI_FLOAT * f_cut); float RC = 1 / ( 2 * M_PIf * f_cut);
return dT / (RC + dT); return dT / (RC + dT);
} }
@ -107,7 +105,7 @@ void biquadFilterInitLPF(biquadFilter_t *filter, float filterFreq, uint32_t refr
void biquadFilterInit(biquadFilter_t *filter, float filterFreq, uint32_t refreshRate, float Q, biquadFilterType_e filterType) void biquadFilterInit(biquadFilter_t *filter, float filterFreq, uint32_t refreshRate, float Q, biquadFilterType_e filterType)
{ {
// setup variables // setup variables
const float omega = 2.0f * M_PI_FLOAT * filterFreq * refreshRate * 0.000001f; const float omega = 2.0f * M_PIf * filterFreq * refreshRate * 0.000001f;
const float sn = sin_approx(omega); const float sn = sin_approx(omega);
const float cs = cos_approx(omega); const float cs = cos_approx(omega);
const float alpha = sn / (2.0f * Q); const float alpha = sn / (2.0f * Q);

3
src/main/common/maths.h
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@ -33,6 +33,9 @@
// Use floating point M_PI instead explicitly. // Use floating point M_PI instead explicitly.
#define M_PIf 3.14159265358979323846f #define M_PIf 3.14159265358979323846f
#define M_EULERf 2.71828182845904523536f
#define M_SQRT2f 1.41421356237309504880f
#define M_LN2f 0.69314718055994530942f
#define RAD (M_PIf / 180.0f) #define RAD (M_PIf / 180.0f)
#define DEGREES_TO_DECIDEGREES(angle) ((angle) * 10) #define DEGREES_TO_DECIDEGREES(angle) ((angle) * 10)

156
src/main/common/sdft.c Normal file
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@ -0,0 +1,156 @@
/*
* This file is part of Cleanflight and Betaflight.
*
* Cleanflight and Betaflight are free software. You can redistribute
* this software and/or modify this software under the terms of the
* GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* Cleanflight and Betaflight are distributed in the hope that they
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software.
*
* If not, see <http://www.gnu.org/licenses/>.
*/
#include <math.h>
#include <stdbool.h>
#include "platform.h"
#include "common/maths.h"
#include "common/sdft.h"
#define SDFT_R 0.9999f // damping factor for guaranteed SDFT stability (r < 1.0f)
static FAST_DATA_ZERO_INIT float rPowerN; // SDFT_R to the power of SDFT_SAMPLE_SIZE
static FAST_DATA_ZERO_INIT bool isInitialized;
static FAST_DATA_ZERO_INIT complex_t twiddle[SDFT_BIN_COUNT];
static void applySqrt(const sdft_t *sdft, float *data);
void sdftInit(sdft_t *sdft, const uint8_t startBin, const uint8_t endBin, const uint8_t numBatches)
{
if (!isInitialized) {
rPowerN = powerf(SDFT_R, SDFT_SAMPLE_SIZE);
const float c = 2.0f * M_PIf / (float)SDFT_SAMPLE_SIZE;
float phi = 0.0f;
for (uint8_t i = 0; i < SDFT_BIN_COUNT; i++) {
phi = c * i;
twiddle[i] = SDFT_R * (cos_approx(phi) + _Complex_I * sin_approx(phi));
}
isInitialized = true;
}
sdft->idx = 0;
sdft->startBin = startBin;
sdft->endBin = endBin;
sdft->numBatches = numBatches;
sdft->batchSize = (sdft->endBin - sdft->startBin + 1) / sdft->numBatches + 1;
for (uint8_t i = 0; i < SDFT_SAMPLE_SIZE; i++) {
sdft->samples[i] = 0.0f;
}
for (uint8_t i = 0; i < SDFT_BIN_COUNT; i++) {
sdft->data[i] = 0.0f;
}
}
// Add new sample to frequency spectrum
FAST_CODE void sdftPush(sdft_t *sdft, const float *sample)
{
const float delta = *sample - rPowerN * sdft->samples[sdft->idx];
sdft->samples[sdft->idx] = *sample;
sdft->idx = (sdft->idx + 1) % SDFT_SAMPLE_SIZE;
for (uint8_t i = sdft->startBin; i <= sdft->endBin; i++) {
sdft->data[i] = twiddle[i] * (sdft->data[i] + delta);
}
}
// Add new sample to frequency spectrum in parts
FAST_CODE void sdftPushBatch(sdft_t* sdft, const float *sample, const uint8_t *batchIdx)
{
const uint8_t batchStart = sdft->batchSize * *batchIdx;
uint8_t batchEnd = batchStart;
const float delta = *sample - rPowerN * sdft->samples[sdft->idx];
if (*batchIdx == sdft->numBatches - 1) {
sdft->samples[sdft->idx] = *sample;
sdft->idx = (sdft->idx + 1) % SDFT_SAMPLE_SIZE;
batchEnd += sdft->endBin - batchStart + 1;
} else {
batchEnd += sdft->batchSize;
}
for (uint8_t i = batchStart; i < batchEnd; i++) {
sdft->data[i] = twiddle[i] * (sdft->data[i] + delta);
}
}
// Get squared magnitude of frequency spectrum
FAST_CODE void sdftMagSq(const sdft_t *sdft, float *output)
{
float re;
float im;
for (uint8_t i = sdft->startBin; i <= sdft->endBin; i++) {
re = crealf(sdft->data[i]);
im = cimagf(sdft->data[i]);
output[i] = re * re + im * im;
}
}
// Get magnitude of frequency spectrum (slower)
FAST_CODE void sdftMagnitude(const sdft_t *sdft, float *output)
{
sdftMagSq(sdft, output);
applySqrt(sdft, output);
}
// Get squared magnitude of frequency spectrum with Hann window applied
// Hann window in frequency domain: X[k] = -0.25 * X[k-1] +0.5 * X[k] -0.25 * X[k+1]
FAST_CODE void sdftWinSq(const sdft_t *sdft, float *output)
{
complex_t val;
float re;
float im;
for (uint8_t i = (sdft->startBin + 1); i < sdft->endBin; i++) {
val = sdft->data[i] - 0.5f * (sdft->data[i - 1] + sdft->data[i + 1]); // multiply by 2 to save one multiplication
re = crealf(val);
im = cimagf(val);
output[i] = re * re + im * im;
}
}
// Get magnitude of frequency spectrum with Hann window applied (slower)
FAST_CODE void sdftWindow(const sdft_t *sdft, float *output)
{
sdftWinSq(sdft, output);
applySqrt(sdft, output);
}
// Apply square root to the whole sdft range
static FAST_CODE void applySqrt(const sdft_t *sdft, float *data)
{
for (uint8_t i = sdft->startBin; i <= sdft->endBin; i++) {
data[i] = sqrtf(data[i]);
}
}

54
src/main/common/sdft.h Normal file
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@ -0,0 +1,54 @@
/*
* This file is part of Cleanflight and Betaflight.
*
* Cleanflight and Betaflight are free software. You can redistribute
* this software and/or modify this software under the terms of the
* GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* Cleanflight and Betaflight are distributed in the hope that they
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software.
*
* If not, see <http://www.gnu.org/licenses/>.
*/
// Implementation of a Sliding Discrete Fourier Transform (SDFT).
// Complexity for calculating frequency spectrum with N bins is O(N).
#pragma once
#include <stdint.h>
#include <complex.h>
#undef I // avoid collision of imaginary unit I with variable I in pid.h
typedef float complex complex_t; // Better readability for type "float complex"
#define SDFT_SAMPLE_SIZE 72
#define SDFT_BIN_COUNT (SDFT_SAMPLE_SIZE / 2)
typedef struct sdft_s {
uint8_t idx; // circular buffer index
uint8_t startBin;
uint8_t endBin;
uint8_t batchSize;
uint8_t numBatches;
float samples[SDFT_SAMPLE_SIZE]; // circular buffer
complex_t data[SDFT_BIN_COUNT]; // complex frequency spectrum
} sdft_t;
STATIC_ASSERT(SDFT_SAMPLE_SIZE <= (uint8_t)-1, window_size_greater_than_underlying_type);
void sdftInit(sdft_t *sdft, const uint8_t startBin, const uint8_t endBin, const uint8_t numBatches);
void sdftPush(sdft_t *sdft, const float *sample);
void sdftPushBatch(sdft_t *sdft, const float *sample, const uint8_t *batchIdx);
void sdftMagSq(const sdft_t *sdft, float *output);
void sdftMagnitude(const sdft_t *sdft, float *output);
void sdftWinSq(const sdft_t *sdft, float *output);
void sdftWindow(const sdft_t *sdft, float *output);

434
src/main/flight/gyroanalyse.c
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@ -19,10 +19,16 @@
*/ */
/* original work by Rav /* original work by Rav
*
* 2018_07 updated by ctzsnooze to post filter, wider Q, different peak detection * 2018_07 updated by ctzsnooze to post filter, wider Q, different peak detection
* coding assistance and advice from DieHertz, Rav, eTracer * coding assistance and advice from DieHertz, Rav, eTracer
* test pilots icr4sh, UAV Tech, Flint723 * test pilots icr4sh, UAV Tech, Flint723
*
* 2021_02 updated by KarateBrot: switched FFT with SDFT, multiple notches per axis
* test pilots: Sugar K, bizmar
*/ */
#include <math.h>
#include <stdint.h> #include <stdint.h>
#include "platform.h" #include "platform.h"
@ -32,6 +38,7 @@
#include "common/filter.h" #include "common/filter.h"
#include "common/maths.h" #include "common/maths.h"
#include "common/sdft.h"
#include "common/time.h" #include "common/time.h"
#include "common/utils.h" #include "common/utils.h"
@ -44,62 +51,72 @@
#include "gyroanalyse.h" #include "gyroanalyse.h"
// FFT_WINDOW_SIZE defaults to 32 (gyroanalyse.h) // SDFT_SAMPLE_SIZE defaults to 72 (common/sdft.h).
// We get 16 frequency bins from 32 consecutive data values // We get 36 frequency bins from 72 consecutive data values, called SDFT_BIN_COUNT (common/sdft.h)
// Bin 0 is DC and can't be used. // Bin 0 is DC and can't be used.
// Only bins 1 to 15 are usable. // Only bins 1 to 35 are usable.
// A gyro sample is collected every gyro loop // A gyro sample is collected every PID loop.
// maxSampleCount recent gyro values are accumulated and averaged // maxSampleCount recent gyro values are accumulated and averaged
// to ensure that 32 samples are collected at the right rate for the required FFT bandwidth // to ensure that 72 samples are collected at the right rate for the required SDFT bandwidth.
// For an 8k gyro loop, at default 600hz max, 6 sequential gyro data points are averaged, FFT runs 1333Hz. // For an 8k PID loop, at default 600hz max, 6 sequential gyro data points are averaged, SDFT runs 1333Hz.
// Upper limit of FFT is half that frequency, eg 666Hz by default. // Upper limit of SDFT is half that frequency, eg 666Hz by default.
// At 8k, if user sets a max of 300Hz, int(8000/600) = 13, fftSamplingRateHz = 615Hz, range 307Hz // At 8k, if user sets a max of 300Hz, int(8000/600) = 13, sdftSampleRateHz = 615Hz, range 307Hz.
// Note that lower max requires more samples to be averaged, increasing precision but taking longer to get enough samples. // Note that lower max requires more samples to be averaged, increasing precision but taking longer to get enough samples.
// For Bosch at 3200Hz gyro, max of 600, int(3200/1200) = 2, fftSamplingRateHz = 1600, range to 800hz // For Bosch at 3200Hz gyro, max of 600, int(3200/1200) = 2, sdftSampleRateHz = 1600, range to 800hz.
// For Bosch on XClass, better to set a max of 300, int(3200/600) = 5, fftSamplingRateHz = 640, range to 320Hz // For Bosch on XClass, better to set a max of 300, int(3200/600) = 5, sdftSampleRateHz = 640, range to 320Hz.
//
// When sampleCount reaches maxSampleCount, the averaged gyro value is put into the circular buffer of 32 samples
// At 8k, with 600Hz max, maxSampleCount = 6, this happens every 6 * 0.125us, or every 0.75ms
// Hence to completely replace all 32 samples of the FFT input buffer with clean new data takes 24ms
// The FFT code is split into steps. It takes 4 gyro loops to calculate the FFT for one axis // When sampleCount reaches maxSampleCount, the averaged gyro value is put into the corresponding SDFT.
// (gyroDataAnalyseUpdate has 8 steps, but only four breaks) // At 8k, with 600Hz max, maxSampleCount = 6, this happens every 6 * 0.125us, or every 0.75ms.
// Since there are three axes, it takes 12 gyro loops to completely update all axes. // Hence to completely replace all 72 samples of the SDFT input buffer with clean new data takes 54ms.
// The SDFT code is split into steps. It takes 4 PID loops to calculate the SDFT, track peaks and update the filters for one axis.
// Since there are three axes, it takes 12 PID loops to completely update all axes.
// At 8k, any one axis gets updated at 8000 / 12 or 666hz or every 1.5ms // At 8k, any one axis gets updated at 8000 / 12 or 666hz or every 1.5ms
// In this time, 2 points in the FFT buffer will have changed. // In this time, 2 points in the SDFT buffer will have changed.
// At 4k, it takes twice as long to update an axis, i.e. each axis updates only every 3ms // At 4k, it takes twice as long to update an axis, i.e. each axis updates only every 3ms.
// Four points in the buffer will have changed in that time, and each point will be the average of three samples. // Four points in the buffer will have changed in that time, and each point will be the average of three samples.
// Hence output jitter at 4k is about four times worse than at 8k. At 2k output jitter is quite bad. // Hence output jitter at 4k is about four times worse than at 8k. At 2k output jitter is quite bad.
// The Hanning window step loads gyro data (32 data points) for one axis from the circular buffer into fftData[i] // Each SDFT output bin has width sdftSampleRateHz/72, ie 18.5Hz per bin at 1333Hz.
// and applies the hanning window to the edge values // Usable bandwidth is half this, ie 666Hz if sdftSampleRateHz is 1333Hz, i.e. bin 1 is 18.5Hz, bin 2 is 37.0Hz etc.
// Calculation steps 1 and 2 then calculate the fft output (32 data points) and put that back into the same fftData[i] array.
// We then use fftData[i] array for frequency centre calculations for that axis
// Each FFT output bin has width fftSamplingRateHz/32, ie 41.65Hz per bin at 1333Hz
// Usable bandwidth is half this, ie 666Hz if fftSamplingRateHz is 1333Hz, i.e. bin 1 is 41.65hz, bin 2 83.3hz etc
#define DYN_NOTCH_SMOOTH_HZ 4 #define DYN_NOTCH_SMOOTH_HZ 4
#define FFT_BIN_COUNT (FFT_WINDOW_SIZE / 2) // 16 #define DYN_NOTCH_CALC_TICKS (XYZ_AXIS_COUNT * STEP_COUNT) // 3 axes and 4 steps per axis
#define DYN_NOTCH_CALC_TICKS (XYZ_AXIS_COUNT * 4) // 4 steps per axis
#define DYN_NOTCH_OSD_MIN_THROTTLE 20 #define DYN_NOTCH_OSD_MIN_THROTTLE 20
static uint16_t FAST_DATA_ZERO_INIT fftSamplingRateHz; typedef enum {
static float FAST_DATA_ZERO_INIT fftResolution;
static uint8_t FAST_DATA_ZERO_INIT fftStartBin; STEP_WINDOW,
static float FAST_DATA_ZERO_INIT dynNotchQ; STEP_DETECT_PEAKS,
static float FAST_DATA_ZERO_INIT dynNotch1Ctr; STEP_CALC_FREQUENCIES,
static float FAST_DATA_ZERO_INIT dynNotch2Ctr; STEP_UPDATE_FILTERS,
STEP_COUNT
} step_e;
typedef struct peak_s {
uint8_t bin;
float value;
} peak_t;
static sdft_t FAST_DATA_ZERO_INIT sdft[XYZ_AXIS_COUNT];
static peak_t FAST_DATA_ZERO_INIT peaks[DYN_NOTCH_COUNT_MAX];
static float FAST_DATA_ZERO_INIT sdftData[SDFT_BIN_COUNT];
static uint16_t FAST_DATA_ZERO_INIT sdftSampleRateHz;
static float FAST_DATA_ZERO_INIT sdftResolutionHz;
static uint8_t FAST_DATA_ZERO_INIT sdftStartBin;
static uint8_t FAST_DATA_ZERO_INIT sdftEndBin;
static float FAST_DATA_ZERO_INIT sdftMeanSq;
static uint16_t FAST_DATA_ZERO_INIT dynNotchBandwidthHz;
static uint16_t FAST_DATA_ZERO_INIT dynNotchMinHz; static uint16_t FAST_DATA_ZERO_INIT dynNotchMinHz;
static uint16_t FAST_DATA_ZERO_INIT dynNotchMaxHz; static uint16_t FAST_DATA_ZERO_INIT dynNotchMaxHz;
static bool FAST_DATA dualNotch = true;
static uint16_t FAST_DATA_ZERO_INIT dynNotchMaxFFT; static uint16_t FAST_DATA_ZERO_INIT dynNotchMaxFFT;
static float FAST_DATA_ZERO_INIT smoothFactor; static float FAST_DATA_ZERO_INIT smoothFactor;
static uint8_t FAST_DATA_ZERO_INIT samples; static uint8_t FAST_DATA_ZERO_INIT numSamples;
// Hanning window, see https://en.wikipedia.org/wiki/Window_function#Hann_.28Hanning.29_window
static FAST_DATA_ZERO_INIT float hanningWindow[FFT_WINDOW_SIZE];
void gyroDataAnalyseInit(uint32_t targetLooptimeUs) void gyroDataAnalyseInit(uint32_t targetLooptimeUs)
{ {
@ -111,33 +128,29 @@ void gyroDataAnalyseInit(uint32_t targetLooptimeUs)
gyroAnalyseInitialized = true; gyroAnalyseInitialized = true;
#endif #endif
dynNotch1Ctr = 1 - gyroConfig()->dyn_notch_width_percent / 100.0f; dynNotchBandwidthHz = gyroConfig()->dyn_notch_bandwidth_hz;
dynNotch2Ctr = 1 + gyroConfig()->dyn_notch_width_percent / 100.0f;
dynNotchQ = gyroConfig()->dyn_notch_q / 100.0f;
dynNotchMinHz = gyroConfig()->dyn_notch_min_hz; dynNotchMinHz = gyroConfig()->dyn_notch_min_hz;
dynNotchMaxHz = MAX(2 * dynNotchMinHz, gyroConfig()->dyn_notch_max_hz); dynNotchMaxHz = MAX(2 * dynNotchMinHz, gyroConfig()->dyn_notch_max_hz);
if (gyroConfig()->dyn_notch_width_percent == 0) { // gyroDataAnalyse() is running at targetLoopRateHz (which is PID loop rate aka. 1e6f/gyro.targetLooptimeUs)
dualNotch = false; const int32_t targetLoopRateHz = lrintf((1.0f / targetLooptimeUs) * 1e6f);
} numSamples = MAX(1, targetLoopRateHz / (2 * dynNotchMaxHz)); // 600hz, 8k looptime, 6.00
const int gyroLoopRateHz = lrintf((1.0f / targetLooptimeUs) * 1e6f); sdftSampleRateHz = targetLoopRateHz / numSamples;
samples = MAX(1, gyroLoopRateHz / (2 * dynNotchMaxHz)); //600hz, 8k looptime, 13.333 // eg 8k, user max 600hz, int(8000/1200) = 6 (6.666), sdftSampleRateHz = 1333hz, range 666Hz
// eg 4k, user max 600hz, int(4000/1200) = 3 (3.333), sdftSampleRateHz = 1333hz, range 666Hz
// eg 2k, user max 600hz, int(2000/1200) = 1 (1.666) sdftSampleRateHz = 2000hz, range 1000Hz
// eg 2k, user max 400hz, int(2000/800) = 2 (2.5) sdftSampleRateHz = 1000hz, range 500Hz
// eg 1k, user max 600hz, int(1000/1200) = 1 (max(1,0.8333)) sdftSampleRateHz = 1000hz, range 500Hz
// the upper limit of DN is always going to be the Nyquist frequency (= sampleRate / 2)
fftSamplingRateHz = gyroLoopRateHz / samples; sdftResolutionHz = (float)sdftSampleRateHz / SDFT_SAMPLE_SIZE; // 13.3hz per bin at 8k
// eg 8k, user max 600hz, int(8000/1200) = 6 (6.666), fftSamplingRateHz = 1333hz, range 666Hz sdftStartBin = MAX(2, lrintf(dynNotchMinHz / sdftResolutionHz + 0.5f)); // can't use bin 0 because it is DC.
// eg 4k, user max 600hz, int(4000/1200) = 3 (3.333), fftSamplingRateHz = 1333hz, range 666Hz sdftEndBin = MIN(SDFT_BIN_COUNT - 1, lrintf(dynNotchMaxHz / sdftResolutionHz + 0.5f)); // can't use more than SDFT_BIN_COUNT bins.
// eg 2k, user max 600hz, int(2000/1200) = 1 (1.666) fftSamplingRateHz = 2000hz, range 1000Hz smoothFactor = pt1FilterGain(DYN_NOTCH_SMOOTH_HZ, DYN_NOTCH_CALC_TICKS / (float)targetLoopRateHz); // minimum PT1 k value
// eg 2k, user max 400hz, int(2000/800) = 2 (2.5) fftSamplingRateHz = 1000hz, range 500Hz
// eg 1k, user max 600hz, int(1000/1200) = 1 (max(1,0.8333)) fftSamplingRateHz = 1000hz, range 500Hz
// the upper limit of DN is always going to be Nyquist
fftResolution = (float)fftSamplingRateHz / FFT_WINDOW_SIZE; // 41.65hz per bin for medium for (uint8_t axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
fftStartBin = MAX(2, dynNotchMinHz / lrintf(fftResolution)); // can't use bin 0 because it is DC. sdftInit(&sdft[axis], sdftStartBin, sdftEndBin, numSamples);
smoothFactor = 2 * M_PIf * DYN_NOTCH_SMOOTH_HZ / (gyroLoopRateHz / 12); // minimum PT1 k value
for (int i = 0; i < FFT_WINDOW_SIZE; i++) {
hanningWindow[i] = (0.5f - 0.5f * cos_approx(2 * M_PIf * i / (FFT_WINDOW_SIZE - 1)));
} }
} }
@ -145,254 +158,217 @@ void gyroDataAnalyseStateInit(gyroAnalyseState_t *state, uint32_t targetLooptime
{ {
// initialise even if FEATURE_DYNAMIC_FILTER not set, since it may be set later // initialise even if FEATURE_DYNAMIC_FILTER not set, since it may be set later
gyroDataAnalyseInit(targetLooptimeUs); gyroDataAnalyseInit(targetLooptimeUs);
state->maxSampleCount = samples; state->maxSampleCount = numSamples;
state->maxSampleCountRcp = 1.0f / state->maxSampleCount; state->maxSampleCountRcp = 1.0f / state->maxSampleCount;
arm_rfft_fast_init_f32(&state->fftInstance, FFT_WINDOW_SIZE);
for (int axis = 0; axis < XYZ_AXIS_COUNT; axis++) { for (uint8_t axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
// any init value for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
state->centerFreq[axis] = dynNotchMaxHz; // any init value is fine, but evenly spreading centerFreqs across frequency range makes notch filters stick to peaks quicker
state->centerFreq[axis][p] = (p + 0.5f) * (dynNotchMaxHz - dynNotchMinHz) / (float)gyro.notchFilterDynCount + dynNotchMinHz;
}
} }
} }
void gyroDataAnalysePush(gyroAnalyseState_t *state, const int axis, const float sample) // Collect gyro data, to be downsampled and analysed in gyroDataAnalyse() function
void gyroDataAnalysePush(gyroAnalyseState_t *state, const uint8_t axis, const float sample)
{ {
state->oversampledGyroAccumulator[axis] += sample; state->oversampledGyroAccumulator[axis] += sample;
} }
static void gyroDataAnalyseUpdate(gyroAnalyseState_t *state, biquadFilter_t *notchFilterDyn, biquadFilter_t *notchFilterDyn2); static void gyroDataAnalyseUpdate(gyroAnalyseState_t *state);
/* // Downsample and analyse gyro data
* Collect gyro data, to be analysed in gyroDataAnalyseUpdate function FAST_CODE void gyroDataAnalyse(gyroAnalyseState_t *state)
*/
void gyroDataAnalyse(gyroAnalyseState_t *state, biquadFilter_t *notchFilterDyn, biquadFilter_t *notchFilterDyn2)
{ {
// samples should have been pushed by `gyroDataAnalysePush` // samples should have been pushed by `gyroDataAnalysePush`
// if gyro sampling is > 1kHz, accumulate and average multiple gyro samples // if gyro sampling is > 1kHz, accumulate and average multiple gyro samples
state->sampleCount++;
if (state->sampleCount == state->maxSampleCount) { if (state->sampleCount == state->maxSampleCount) {
state->sampleCount = 0; state->sampleCount = 0;
// calculate mean value of accumulated samples // calculate mean value of accumulated samples
for (int axis = 0; axis < XYZ_AXIS_COUNT; axis++) { for (uint8_t axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
float sample = state->oversampledGyroAccumulator[axis] * state->maxSampleCountRcp; const float sample = state->oversampledGyroAccumulator[axis] * state->maxSampleCountRcp;
state->downsampledGyroData[axis][state->circularBufferIdx] = sample; state->downsampledGyroData[axis] = sample;
if (axis == 0) { if (axis == 0) {
DEBUG_SET(DEBUG_FFT, 2, lrintf(sample)); DEBUG_SET(DEBUG_FFT, 2, lrintf(sample));
} }
state->oversampledGyroAccumulator[axis] = 0; state->oversampledGyroAccumulator[axis] = 0;
} }
state->circularBufferIdx = (state->circularBufferIdx + 1) % FFT_WINDOW_SIZE; // We need DYN_NOTCH_CALC_TICKS ticks to update all axes with newly sampled value
// We need DYN_NOTCH_CALC_TICKS tick to update all axis with newly sampled value
// recalculation of filters takes 4 calls per axis => each filter gets updated every DYN_NOTCH_CALC_TICKS calls // recalculation of filters takes 4 calls per axis => each filter gets updated every DYN_NOTCH_CALC_TICKS calls
// at 4kHz gyro loop rate this means 8kHz / 4 / 3 = 666Hz => update every 1.5ms // at 8kHz PID loop rate this means 8kHz / 4 / 3 = 666Hz => update every 1.5ms
// at 4kHz gyro loop rate this means 4kHz / 4 / 3 = 333Hz => update every 3ms // at 4kHz PID loop rate this means 4kHz / 4 / 3 = 333Hz => update every 3ms
state->updateTicks = DYN_NOTCH_CALC_TICKS; state->updateTicks = DYN_NOTCH_CALC_TICKS;
} }
// calculate FFT and update filters // 2us @ F722
// SDFT processing in batches to synchronize with incoming downsampled data
for (uint8_t axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
sdftPushBatch(&sdft[axis], &state->downsampledGyroData[axis], &state->sampleCount);
}
state->sampleCount++;
// Find frequency peaks and update filters
if (state->updateTicks > 0) { if (state->updateTicks > 0) {
gyroDataAnalyseUpdate(state, notchFilterDyn, notchFilterDyn2); gyroDataAnalyseUpdate(state);
--state->updateTicks; --state->updateTicks;
} }
} }
void stage_rfft_f32(arm_rfft_fast_instance_f32 *S, float32_t *p, float32_t *pOut); // Find frequency peaks and update filters
void arm_cfft_radix8by2_f32(arm_cfft_instance_f32 *S, float32_t *p1); static FAST_CODE_NOINLINE void gyroDataAnalyseUpdate(gyroAnalyseState_t *state)
void arm_cfft_radix8by4_f32(arm_cfft_instance_f32 *S, float32_t *p1);
void arm_radix8_butterfly_f32(float32_t *pSrc, uint16_t fftLen, const float32_t *pCoef, uint16_t twidCoefModifier);
void arm_bitreversal_32(uint32_t *pSrc, const uint16_t bitRevLen, const uint16_t *pBitRevTable);
/*
* Analyse gyro data
*/
static FAST_CODE_NOINLINE void gyroDataAnalyseUpdate(gyroAnalyseState_t *state, biquadFilter_t *notchFilterDyn, biquadFilter_t *notchFilterDyn2)
{ {
enum {
STEP_ARM_CFFT_F32,
STEP_BITREVERSAL,
STEP_STAGE_RFFT_F32,
STEP_ARM_CMPLX_MAG_F32,
STEP_CALC_FREQUENCIES,
STEP_UPDATE_FILTERS,
STEP_HANNING,
STEP_COUNT
};
arm_cfft_instance_f32 *Sint = &(state->fftInstance.Sint);
uint32_t startTime = 0; uint32_t startTime = 0;
if (debugMode == (DEBUG_FFT_TIME)) { if (debugMode == (DEBUG_FFT_TIME)) {
startTime = micros(); startTime = micros();
} }
DEBUG_SET(DEBUG_FFT_TIME, 0, state->updateStep); DEBUG_SET(DEBUG_FFT_TIME, 0, state->updateStep);
switch (state->updateStep) { switch (state->updateStep) {
case STEP_ARM_CFFT_F32:
case STEP_WINDOW: // 6us @ F722
{ {
switch (FFT_BIN_COUNT) { sdftWinSq(&sdft[state->updateAxis], sdftData);
case 16:
// 16us // Calculate mean square over frequency range (= average power of vibrations)
arm_cfft_radix8by2_f32(Sint, state->fftData); sdftMeanSq = 0.0f;
break; for (uint8_t bin = (sdftStartBin + 1); bin < sdftEndBin; bin++) { // don't use startBin or endBin because they are not windowed properly
case 32: sdftMeanSq += sdftData[bin]; // sdftData is already squared (see sdftWinSq)
// 35us
arm_cfft_radix8by4_f32(Sint, state->fftData);
break;
case 64:
// 70us
arm_radix8_butterfly_f32(state->fftData, FFT_BIN_COUNT, Sint->pTwiddle, 1);
break;
} }
sdftMeanSq /= sdftEndBin - sdftStartBin - 1;
DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime); DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime);
break; break;
} }
case STEP_BITREVERSAL: case STEP_DETECT_PEAKS: // 6us @ F722
{ {
// 6us // Get memory ready for new peak data on current axis
arm_bitreversal_32((uint32_t*) state->fftData, Sint->bitRevLength, Sint->pBitRevTable); for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime); peaks[p].bin = 0;
state->updateStep++; peaks[p].value = 0.0f;
FALLTHROUGH;
} }
case STEP_STAGE_RFFT_F32:
{ // Search for N biggest peaks in frequency spectrum
// 14us for (uint8_t bin = (sdftStartBin + 1); bin < sdftEndBin; bin++) {
// this does not work in place => fftData AND rfftData needed // Check if bin is peak
stage_rfft_f32(&state->fftInstance, state->fftData, state->rfftData); if ((sdftData[bin] > sdftData[bin - 1]) && (sdftData[bin] > sdftData[bin + 1])) {
// Check if peak is big enough to be one of N biggest peaks.
// If so, insert peak and sort peaks in descending height order
for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
if (sdftData[bin] > peaks[p].value) {
for (uint8_t k = gyro.notchFilterDynCount - 1; k > p; k--) {
peaks[k] = peaks[k - 1];
}
peaks[p].bin = bin;
peaks[p].value = sdftData[bin];
break;
}
}
bin++; // If bin is peak, next bin can't be peak => jump it
}
}
// Sort N biggest peaks in ascending bin order (example: 3, 8, 25, 0, 0, ..., 0)
for (uint8_t p = gyro.notchFilterDynCount - 1; p > 0; p--) {
for (uint8_t k = 0; k < p; k++) {
// Swap peaks but ignore swapping void peaks (bin = 0). This leaves
// void peaks at the end of peaks array without moving them
if (peaks[k].bin > peaks[k + 1].bin && peaks[k + 1].bin != 0) {
peak_t temp = peaks[k];
peaks[k] = peaks[k + 1];
peaks[k + 1] = temp;
}
}
}
DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime); DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime);
break; break;
} }
case STEP_ARM_CMPLX_MAG_F32: case STEP_CALC_FREQUENCIES: // 4us @ F722
{ {
// 8us for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
arm_cmplx_mag_f32(state->rfftData, state->fftData, FFT_BIN_COUNT);
DEBUG_SET(DEBUG_FFT_TIME, 2, micros() - startTime);
state->updateStep++;
FALLTHROUGH;
}
case STEP_CALC_FREQUENCIES:
{
// identify max bin and max/min heights
float dataMax = 0.0f;
float dataMin = 1.0f;
uint8_t binMax = 0;
float dataMinHi = 1.0f;
for (int i = fftStartBin; i < FFT_BIN_COUNT; i++) {
if (state->fftData[i] > state->fftData[i - 1]) { // bin height increased
if (state->fftData[i] > dataMax) {
dataMax = state->fftData[i];
binMax = i; // tallest bin so far
}
}
}
if (binMax == 0) { // no bin increase, hold prev max bin, dataMin = 1 dataMax = 0, ie move slow
binMax = lrintf(state->centerFreq[state->updateAxis] / fftResolution);
} else { // there was a max, find min
for (int i = binMax - 1; i > 1; i--) { // look for min below max
dataMin = state->fftData[i];
if (state->fftData[i - 1] > state->fftData[i]) { // up step below this one
break;
}
}
for (int i = binMax + 1; i < (FFT_BIN_COUNT - 1); i++) { // // look for min above max
dataMinHi = state->fftData[i];
if (state->fftData[i] < state->fftData[i + 1]) { // up step above this one
break;
}
}
}
dataMin = fminf(dataMin, dataMinHi);
// accumulate fftSum and fftWeightedSum from peak bin, and shoulder bins either side of peak // Only update state->centerFreq if there is a peak (ignore void peaks) and if peak is above noise floor
float squaredData = state->fftData[binMax] * state->fftData[binMax]; if (peaks[p].bin != 0 && peaks[p].value > sdftMeanSq) {
float fftSum = squaredData;
float fftWeightedSum = squaredData * binMax;
// accumulate upper shoulder unless it would be FFT_BIN_COUNT // accumulate sdftSum and sdftWeightedSum from peak bin, and shoulder bins either side of peak
uint8_t shoulderBin = binMax + 1; float squaredData = peaks[p].value; // peak data already squared (see sdftWinSq)
if (shoulderBin < FFT_BIN_COUNT) { float sdftSum = squaredData;
squaredData = state->fftData[shoulderBin] * state->fftData[shoulderBin]; float sdftWeightedSum = squaredData * peaks[p].bin;
fftSum += squaredData;
fftWeightedSum += squaredData * shoulderBin; // accumulate upper shoulder unless it would be sdftEndBin
uint8_t shoulderBin = peaks[p].bin + 1;
if (shoulderBin < sdftEndBin) {
squaredData = sdftData[shoulderBin]; // sdftData already squared (see sdftWinSq)
sdftSum += squaredData;
sdftWeightedSum += squaredData * shoulderBin;
} }
// accumulate lower shoulder unless lower shoulder would be bin 0 (DC) // accumulate lower shoulder unless lower shoulder would be bin 0 (DC)
if (binMax > 1) { if (peaks[p].bin > 1) {
shoulderBin = binMax - 1; shoulderBin = peaks[p].bin - 1;
squaredData = state->fftData[shoulderBin] * state->fftData[shoulderBin]; squaredData = sdftData[shoulderBin]; // sdftData already squared (see sdftWinSq)
fftSum += squaredData; sdftSum += squaredData;
fftWeightedSum += squaredData * shoulderBin; sdftWeightedSum += squaredData * shoulderBin;
} }
// get centerFreq in Hz from weighted bins // get centerFreq in Hz from weighted bins
float centerFreq = dynNotchMaxHz; float centerFreq = dynNotchMaxHz;
float fftMeanIndex = 0; float sdftMeanBin = 0;
if (fftSum > 0) {
fftMeanIndex = (fftWeightedSum / fftSum); if (sdftSum > 0) {
centerFreq = fftMeanIndex * fftResolution; sdftMeanBin = (sdftWeightedSum / sdftSum);
// In theory, the index points to the centre frequency of the bin. centerFreq = sdftMeanBin * sdftResolutionHz;
// at 1333hz, bin widths are 41.65Hz, so bin 2 has the range 83,3Hz to 124,95Hz
// Rav feels that maybe centerFreq = (fftMeanIndex + 0.5) * fftResolution; is better
// empirical checking shows that not adding 0.5 works better
} else {
centerFreq = state->centerFreq[state->updateAxis];
}
centerFreq = constrainf(centerFreq, dynNotchMinHz, dynNotchMaxHz); centerFreq = constrainf(centerFreq, dynNotchMinHz, dynNotchMaxHz);
// In theory, the index points to the centre frequency of the bin.
// at 1333hz, bin widths are 13.3Hz, so bin 2 (26.7Hz) has the range 20Hz to 33.3Hz
// Rav feels that maybe centerFreq = (sdftMeanBin + 0.5) * sdftResolutionHz is better
// empirical checking shows that not adding 0.5 works better
// PT1 style dynamic smoothing moves rapidly towards big peaks and slowly away, up to 8x faster // PT1 style dynamic smoothing moves rapidly towards big peaks and slowly away, up to 8x faster
float dynamicFactor = constrainf(dataMax / dataMin, 1.0f, 8.0f); // DYN_NOTCH_SMOOTH_HZ = 4 & dynamicFactor = 1 .. 8 => PT1 -3dB cutoff frequency = 4Hz .. 41Hz
state->centerFreq[state->updateAxis] = state->centerFreq[state->updateAxis] + smoothFactor * dynamicFactor * (centerFreq - state->centerFreq[state->updateAxis]); const float dynamicFactor = constrainf(peaks[p].value / sdftMeanSq, 1.0f, 8.0f);
state->centerFreq[state->updateAxis][p] += smoothFactor * dynamicFactor * (centerFreq - state->centerFreq[state->updateAxis][p]);
}
}
}
if(calculateThrottlePercentAbs() > DYN_NOTCH_OSD_MIN_THROTTLE) { if(calculateThrottlePercentAbs() > DYN_NOTCH_OSD_MIN_THROTTLE) {
dynNotchMaxFFT = MAX(dynNotchMaxFFT, state->centerFreq[state->updateAxis]); for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
dynNotchMaxFFT = MAX(dynNotchMaxFFT, state->centerFreq[state->updateAxis][p]);
}
} }
if (state->updateAxis == 0) { if (state->updateAxis == gyro.gyroDebugAxis) {
DEBUG_SET(DEBUG_FFT, 3, lrintf(fftMeanIndex * 100)); for (uint8_t p = 0; p < gyro.notchFilterDynCount && p < 3; p++) {
DEBUG_SET(DEBUG_FFT_FREQ, 0, state->centerFreq[state->updateAxis]); DEBUG_SET(DEBUG_FFT_FREQ, p, lrintf(state->centerFreq[state->updateAxis][p]));
DEBUG_SET(DEBUG_FFT_FREQ, 1, lrintf(dynamicFactor * 100));
DEBUG_SET(DEBUG_DYN_LPF, 1, state->centerFreq[state->updateAxis]);
} }
// if (state->updateAxis == 1) { DEBUG_SET(DEBUG_DYN_LPF, 1, lrintf(state->centerFreq[state->updateAxis][0]));
// DEBUG_SET(DEBUG_FFT_FREQ, 1, state->centerFreq[state->updateAxis]); }
// }
DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime); DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime);
break; break;
} }
case STEP_UPDATE_FILTERS: case STEP_UPDATE_FILTERS: // 7us @ F722
{ {
// 7us for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
// calculate cutoffFreq and notch Q, update notch filter // Only update notch filter coefficients if the corresponding peak got its center frequency updated in the previous step
if (dualNotch) { if (peaks[p].bin != 0 && peaks[p].value > sdftMeanSq) {
biquadFilterUpdate(&notchFilterDyn[state->updateAxis], state->centerFreq[state->updateAxis] * dynNotch1Ctr, gyro.targetLooptime, dynNotchQ, FILTER_NOTCH); // Choose notch Q in such a way that notch bandwidth stays constant (improves prop wash handling)
biquadFilterUpdate(&notchFilterDyn2[state->updateAxis], state->centerFreq[state->updateAxis] * dynNotch2Ctr, gyro.targetLooptime, dynNotchQ, FILTER_NOTCH); float dynamicQ = state->centerFreq[state->updateAxis][p] / (float)dynNotchBandwidthHz;
} else { dynamicQ = constrainf(dynamicQ, 2.0f, 10.0f);
biquadFilterUpdate(&notchFilterDyn[state->updateAxis], state->centerFreq[state->updateAxis], gyro.targetLooptime, dynNotchQ, FILTER_NOTCH); biquadFilterUpdate(&gyro.notchFilterDyn[state->updateAxis][p], state->centerFreq[state->updateAxis][p], gyro.targetLooptime, dynamicQ, FILTER_NOTCH);
} }
}
DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime); DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime);
state->updateAxis = (state->updateAxis + 1) % XYZ_AXIS_COUNT; state->updateAxis = (state->updateAxis + 1) % XYZ_AXIS_COUNT;
state->updateStep++;
FALLTHROUGH;
}
case STEP_HANNING:
{
// 5us
// apply hanning window to gyro samples and store result in fftData[i] to be used in step 1 and 2 and 3
const uint8_t ringBufIdx = FFT_WINDOW_SIZE - state->circularBufferIdx;
arm_mult_f32(&state->downsampledGyroData[state->updateAxis][state->circularBufferIdx], &hanningWindow[0], &state->fftData[0], ringBufIdx);
if (state->circularBufferIdx > 0) {
arm_mult_f32(&state->downsampledGyroData[state->updateAxis][0], &hanningWindow[ringBufIdx], &state->fftData[ringBufIdx], state->circularBufferIdx);
}
DEBUG_SET(DEBUG_FFT_TIME, 1, micros() - startTime);
} }
} }

24
src/main/flight/gyroanalyse.h
View File

@ -20,40 +20,30 @@
#pragma once #pragma once
#include "arm_math.h" #define DYN_NOTCH_COUNT_MAX 5
#include "common/filter.h"
#define FFT_WINDOW_SIZE 32
typedef struct gyroAnalyseState_s { typedef struct gyroAnalyseState_s {
// accumulator for oversampled data => no aliasing and less noise // accumulator for oversampled data => no aliasing and less noise
uint8_t sampleCount; uint8_t sampleCount;
uint8_t maxSampleCount; uint8_t maxSampleCount;
float maxSampleCountRcp; float maxSampleCountRcp;
float oversampledGyroAccumulator[XYZ_AXIS_COUNT]; float oversampledGyroAccumulator[XYZ_AXIS_COUNT];
// downsampled gyro data circular buffer for frequency analysis // downsampled gyro data for frequency analysis
uint8_t circularBufferIdx; float downsampledGyroData[XYZ_AXIS_COUNT];
float downsampledGyroData[XYZ_AXIS_COUNT][FFT_WINDOW_SIZE];
// update state machine step information // update state machine step information
uint8_t updateTicks; uint8_t updateTicks;
uint8_t updateStep; uint8_t updateStep;
uint8_t updateAxis; uint8_t updateAxis;
arm_rfft_fast_instance_f32 fftInstance; float centerFreq[XYZ_AXIS_COUNT][DYN_NOTCH_COUNT_MAX];
float fftData[FFT_WINDOW_SIZE];
float rfftData[FFT_WINDOW_SIZE];
float centerFreq[XYZ_AXIS_COUNT];
} gyroAnalyseState_t; } gyroAnalyseState_t;
STATIC_ASSERT(FFT_WINDOW_SIZE <= (uint8_t) -1, window_size_greater_than_underlying_type);
void gyroDataAnalyseStateInit(gyroAnalyseState_t *state, uint32_t targetLooptimeUs); void gyroDataAnalyseStateInit(gyroAnalyseState_t *state, uint32_t targetLooptimeUs);
void gyroDataAnalysePush(gyroAnalyseState_t *state, const int axis, const float sample); void gyroDataAnalysePush(gyroAnalyseState_t *state, const uint8_t axis, const float sample);
void gyroDataAnalyse(gyroAnalyseState_t *state, biquadFilter_t *notchFilterDyn, biquadFilter_t *notchFilterDyn2); void gyroDataAnalyse(gyroAnalyseState_t *state);
uint16_t getMaxFFT(void); uint16_t getMaxFFT(void);
void resetMaxFFT(void); void resetMaxFFT(void);

26
src/main/msp/msp.c
View File

@ -1771,8 +1771,8 @@ static bool mspProcessOutCommand(int16_t cmdMSP, sbuf_t *dst)
// Added in MSP API 1.42 // Added in MSP API 1.42
#if defined(USE_GYRO_DATA_ANALYSE) #if defined(USE_GYRO_DATA_ANALYSE)
sbufWriteU8(dst, 0); // DEPRECATED 1.43: dyn_notch_range sbufWriteU8(dst, 0); // DEPRECATED 1.43: dyn_notch_range
sbufWriteU8(dst, gyroConfig()->dyn_notch_width_percent); sbufWriteU8(dst, 0); // DEPRECATED 1.44: dyn_notch_width_percent
sbufWriteU16(dst, gyroConfig()->dyn_notch_q); sbufWriteU16(dst, 0); // DEPRECATED 1.44: dyn_notch_q
sbufWriteU16(dst, gyroConfig()->dyn_notch_min_hz); sbufWriteU16(dst, gyroConfig()->dyn_notch_min_hz);
#else #else
sbufWriteU8(dst, 0); sbufWriteU8(dst, 0);
@ -1799,6 +1799,13 @@ static bool mspProcessOutCommand(int16_t cmdMSP, sbuf_t *dst)
#else #else
sbufWriteU8(dst, 0); sbufWriteU8(dst, 0);
#endif #endif
#if defined(USE_GYRO_DATA_ANALYSE)
sbufWriteU8(dst, gyroConfig()->dyn_notch_count);
sbufWriteU16(dst, gyroConfig()->dyn_notch_bandwidth_hz);
#else
sbufWriteU8(dst, 0);
sbufWriteU16(dst, 0);
#endif
break; break;
case MSP_PID_ADVANCED: case MSP_PID_ADVANCED:
@ -2635,9 +2642,9 @@ static mspResult_e mspProcessInCommand(mspDescriptor_t srcDesc, int16_t cmdMSP,
if (sbufBytesRemaining(src) >= 8) { if (sbufBytesRemaining(src) >= 8) {
// Added in MSP API 1.42 // Added in MSP API 1.42
#if defined(USE_GYRO_DATA_ANALYSE) #if defined(USE_GYRO_DATA_ANALYSE)
sbufReadU8(src); // DEPRECATED: dyn_notch_range sbufReadU8(src); // DEPRECATED 1.43: dyn_notch_range
gyroConfigMutable()->dyn_notch_width_percent = sbufReadU8(src); sbufReadU8(src); // DEPRECATED 1.44: dyn_notch_width_percent
gyroConfigMutable()->dyn_notch_q = sbufReadU16(src); sbufReadU16(src); // DEPRECATED 1.44: dyn_notch_q
gyroConfigMutable()->dyn_notch_min_hz = sbufReadU16(src); gyroConfigMutable()->dyn_notch_min_hz = sbufReadU16(src);
#else #else
sbufReadU8(src); sbufReadU8(src);
@ -2661,12 +2668,19 @@ static mspResult_e mspProcessInCommand(mspDescriptor_t srcDesc, int16_t cmdMSP,
sbufReadU16(src); sbufReadU16(src);
#endif #endif
} }
if (sbufBytesRemaining(src) >= 1) { if (sbufBytesRemaining(src) >= 4) {
// Added in MSP API 1.44 // Added in MSP API 1.44
#if defined(USE_DYN_LPF) #if defined(USE_DYN_LPF)
currentPidProfile->dyn_lpf_curve_expo = sbufReadU8(src); currentPidProfile->dyn_lpf_curve_expo = sbufReadU8(src);
#else #else
sbufReadU8(src); sbufReadU8(src);
#endif
#if defined(USE_GYRO_DATA_ANALYSE)
gyroConfigMutable()->dyn_notch_count = sbufReadU8(src);
gyroConfigMutable()->dyn_notch_bandwidth_hz = sbufReadU16(src);
#else
sbufReadU8(src);
sbufReadU16(src);
#endif #endif
} }

8
src/main/sensors/gyro.c
View File

@ -98,7 +98,7 @@ STATIC_UNIT_TESTED gyroDev_t * const gyroDevPtr = &gyro.gyroSensor1.gyroDev;
#define GYRO_OVERFLOW_TRIGGER_THRESHOLD 31980 // 97.5% full scale (1950dps for 2000dps gyro) #define GYRO_OVERFLOW_TRIGGER_THRESHOLD 31980 // 97.5% full scale (1950dps for 2000dps gyro)
#define GYRO_OVERFLOW_RESET_THRESHOLD 30340 // 92.5% full scale (1850dps for 2000dps gyro) #define GYRO_OVERFLOW_RESET_THRESHOLD 30340 // 92.5% full scale (1850dps for 2000dps gyro)
PG_REGISTER_WITH_RESET_FN(gyroConfig_t, gyroConfig, PG_GYRO_CONFIG, 8); PG_REGISTER_WITH_RESET_FN(gyroConfig_t, gyroConfig, PG_GYRO_CONFIG, 9);
#ifndef GYRO_CONFIG_USE_GYRO_DEFAULT #ifndef GYRO_CONFIG_USE_GYRO_DEFAULT
#define GYRO_CONFIG_USE_GYRO_DEFAULT GYRO_CONFIG_USE_GYRO_1 #define GYRO_CONFIG_USE_GYRO_DEFAULT GYRO_CONFIG_USE_GYRO_1
@ -129,8 +129,8 @@ void pgResetFn_gyroConfig(gyroConfig_t *gyroConfig)
gyroConfig->dyn_lpf_gyro_min_hz = DYN_LPF_GYRO_MIN_HZ_DEFAULT; gyroConfig->dyn_lpf_gyro_min_hz = DYN_LPF_GYRO_MIN_HZ_DEFAULT;
gyroConfig->dyn_lpf_gyro_max_hz = DYN_LPF_GYRO_MAX_HZ_DEFAULT; gyroConfig->dyn_lpf_gyro_max_hz = DYN_LPF_GYRO_MAX_HZ_DEFAULT;
gyroConfig->dyn_notch_max_hz = 600; gyroConfig->dyn_notch_max_hz = 600;
gyroConfig->dyn_notch_width_percent = 8; gyroConfig->dyn_notch_count = 1;
gyroConfig->dyn_notch_q = 120; gyroConfig->dyn_notch_bandwidth_hz = 45;
gyroConfig->dyn_notch_min_hz = 150; gyroConfig->dyn_notch_min_hz = 150;
gyroConfig->gyro_filter_debug_axis = FD_ROLL; gyroConfig->gyro_filter_debug_axis = FD_ROLL;
gyroConfig->dyn_lpf_curve_expo = 5; gyroConfig->dyn_lpf_curve_expo = 5;
@ -484,7 +484,7 @@ FAST_CODE void gyroFiltering(timeUs_t currentTimeUs)
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
if (isDynamicFilterActive()) { if (isDynamicFilterActive()) {
gyroDataAnalyse(&gyro.gyroAnalyseState, gyro.notchFilterDyn, gyro.notchFilterDyn2); gyroDataAnalyse(&gyro.gyroAnalyseState);
} }
#endif #endif

13
src/main/sensors/gyro.h
View File

@ -107,12 +107,11 @@ typedef struct gyro_s {
filterApplyFnPtr notchFilter2ApplyFn; filterApplyFnPtr notchFilter2ApplyFn;
biquadFilter_t notchFilter2[XYZ_AXIS_COUNT]; biquadFilter_t notchFilter2[XYZ_AXIS_COUNT];
filterApplyFnPtr notchFilterDynApplyFn;
filterApplyFnPtr notchFilterDynApplyFn2;
biquadFilter_t notchFilterDyn[XYZ_AXIS_COUNT];
biquadFilter_t notchFilterDyn2[XYZ_AXIS_COUNT];
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
filterApplyFnPtr notchFilterDynApplyFn;
biquadFilter_t notchFilterDyn[XYZ_AXIS_COUNT][DYN_NOTCH_COUNT_MAX];
uint8_t notchFilterDynCount;
gyroAnalyseState_t gyroAnalyseState; gyroAnalyseState_t gyroAnalyseState;
#endif #endif
@ -196,8 +195,8 @@ typedef struct gyroConfig_s {
uint16_t dyn_lpf_gyro_max_hz; uint16_t dyn_lpf_gyro_max_hz;
uint16_t dyn_notch_max_hz; uint16_t dyn_notch_max_hz;
uint8_t dyn_notch_width_percent; uint8_t dyn_notch_count;
uint16_t dyn_notch_q; uint16_t dyn_notch_bandwidth_hz;
uint16_t dyn_notch_min_hz; uint16_t dyn_notch_min_hz;
uint8_t gyro_filter_debug_axis; uint8_t gyro_filter_debug_axis;

25
src/main/sensors/gyro_filter_impl.c
View File

@ -49,16 +49,6 @@ static FAST_CODE void GYRO_FILTER_FUNCTION_NAME(void)
// DEBUG_GYRO_SAMPLE(1) Record the post-downsample value for the selected debug axis // DEBUG_GYRO_SAMPLE(1) Record the post-downsample value for the selected debug axis
GYRO_FILTER_AXIS_DEBUG_SET(axis, DEBUG_GYRO_SAMPLE, 1, lrintf(gyroADCf)); GYRO_FILTER_AXIS_DEBUG_SET(axis, DEBUG_GYRO_SAMPLE, 1, lrintf(gyroADCf));
#ifdef USE_GYRO_DATA_ANALYSE
if (isDynamicFilterActive()) {
if (axis == gyro.gyroDebugAxis) {
GYRO_FILTER_DEBUG_SET(DEBUG_FFT, 0, lrintf(gyroADCf));
GYRO_FILTER_DEBUG_SET(DEBUG_FFT_FREQ, 3, lrintf(gyroADCf));
GYRO_FILTER_DEBUG_SET(DEBUG_DYN_LPF, 0, lrintf(gyroADCf));
}
}
#endif
#ifdef USE_RPM_FILTER #ifdef USE_RPM_FILTER
gyroADCf = rpmFilterGyro(axis, gyroADCf); gyroADCf = rpmFilterGyro(axis, gyroADCf);
#endif #endif
@ -76,14 +66,21 @@ static FAST_CODE void GYRO_FILTER_FUNCTION_NAME(void)
#ifdef USE_GYRO_DATA_ANALYSE #ifdef USE_GYRO_DATA_ANALYSE
if (isDynamicFilterActive()) { if (isDynamicFilterActive()) {
if (axis == gyro.gyroDebugAxis) {
GYRO_FILTER_DEBUG_SET(DEBUG_FFT, 0, lrintf(gyroADCf));
GYRO_FILTER_DEBUG_SET(DEBUG_FFT_FREQ, 3, lrintf(gyroADCf));
GYRO_FILTER_DEBUG_SET(DEBUG_DYN_LPF, 0, lrintf(gyroADCf));
}
gyroDataAnalysePush(&gyro.gyroAnalyseState, axis, gyroADCf);
for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
gyroADCf = gyro.notchFilterDynApplyFn((filter_t*)&gyro.notchFilterDyn[axis][p], gyroADCf);
}
if (axis == gyro.gyroDebugAxis) { if (axis == gyro.gyroDebugAxis) {
GYRO_FILTER_DEBUG_SET(DEBUG_FFT, 1, lrintf(gyroADCf)); GYRO_FILTER_DEBUG_SET(DEBUG_FFT, 1, lrintf(gyroADCf));
GYRO_FILTER_DEBUG_SET(DEBUG_FFT_FREQ, 2, lrintf(gyroADCf));
GYRO_FILTER_DEBUG_SET(DEBUG_DYN_LPF, 3, lrintf(gyroADCf)); GYRO_FILTER_DEBUG_SET(DEBUG_DYN_LPF, 3, lrintf(gyroADCf));
} }
gyroDataAnalysePush(&gyro.gyroAnalyseState, axis, gyroADCf);
gyroADCf = gyro.notchFilterDynApplyFn((filter_t *)&gyro.notchFilterDyn[axis], gyroADCf);
gyroADCf = gyro.notchFilterDynApplyFn2((filter_t *)&gyro.notchFilterDyn2[axis], gyroADCf);
} }
#endif #endif

13
src/main/sensors/gyro_init.c
View File

@ -133,17 +133,16 @@ static void gyroInitFilterNotch2(uint16_t notchHz, uint16_t notchCutoffHz)
static void gyroInitFilterDynamicNotch() static void gyroInitFilterDynamicNotch()
{ {
gyro.notchFilterDynApplyFn = nullFilterApply; gyro.notchFilterDynApplyFn = nullFilterApply;
gyro.notchFilterDynApplyFn2 = nullFilterApply;
if (isDynamicFilterActive()) { if (isDynamicFilterActive()) {
gyro.notchFilterDynApplyFn = (filterApplyFnPtr)biquadFilterApplyDF1; // must be this function, not DF2 gyro.notchFilterDynApplyFn = (filterApplyFnPtr)biquadFilterApplyDF1; // must be this function, not DF2
if(gyroConfig()->dyn_notch_width_percent != 0) { gyro.notchFilterDynCount = gyroConfig()->dyn_notch_count;
gyro.notchFilterDynApplyFn2 = (filterApplyFnPtr)biquadFilterApplyDF1; // must be this function, not DF2
}
const float notchQ = filterGetNotchQ(DYNAMIC_NOTCH_DEFAULT_CENTER_HZ, DYNAMIC_NOTCH_DEFAULT_CUTOFF_HZ); // any defaults OK here const float notchQ = filterGetNotchQ(DYNAMIC_NOTCH_DEFAULT_CENTER_HZ, DYNAMIC_NOTCH_DEFAULT_CUTOFF_HZ); // any defaults OK here
for (int axis = 0; axis < XYZ_AXIS_COUNT; axis++) { for (uint8_t axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
biquadFilterInit(&gyro.notchFilterDyn[axis], DYNAMIC_NOTCH_DEFAULT_CENTER_HZ, gyro.targetLooptime, notchQ, FILTER_NOTCH); for (uint8_t p = 0; p < gyro.notchFilterDynCount; p++) {
biquadFilterInit(&gyro.notchFilterDyn2[axis], DYNAMIC_NOTCH_DEFAULT_CENTER_HZ, gyro.targetLooptime, notchQ, FILTER_NOTCH); biquadFilterInit(&gyro.notchFilterDyn[axis][p], DYNAMIC_NOTCH_DEFAULT_CENTER_HZ, gyro.targetLooptime, notchQ, FILTER_NOTCH);
}
} }
} }
} }