PQ_Hybrid_Electrical_Equipment_Team / MadgwickFilter

Madgwick Filterをライブラリ化しました．内容はオープンソースになっていたやつのほぼ同じです．

Dependencies:   Quaternion

Dependents:   Hybrid_main_FirstEdtion rocket_logger_sinkan2018_v1 HYBRYD2018_IZU_ROCKET Hybrid_IZU2019 ... more

Fork of MadgwickFilter by Gaku Matsumoto

MadgwickFilter.hpp@7:c20656d96585, 2018-02-28 (annotated)

Committer:
Gaku0606
Date:
Wed Feb 28 17:10:35 2018 +0000
Revision:
7:c20656d96585
Parent:
6:eff5ebc4ea13 
kkk

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Gaku0606 0:c160cac4c370 1 #ifndef _MADGWICK_FILTER_HPP_
Gaku0606 0:c160cac4c370 2 #define _MADGWICK_FILTER_HPP_
Gaku0606 0:c160cac4c370 3
Gaku0606 0:c160cac4c370 4 #include "mbed.h"
Gaku0606 0:c160cac4c370 5 #include "Quaternion.hpp"
Gaku0606 0:c160cac4c370 6
Gaku0606 0:c160cac4c370 7 #define BETA_DEF 0.1
Gaku0606 0:c160cac4c370 8
Gaku0606 0:c160cac4c370 9 /**
Gaku0606 2:e1de76e257f6 10 * @bref Madgwick Filterを用いて，角速度・加速度・地磁気データを統合し，姿勢を推定するライブラリです．
Gaku0606 2:e1de76e257f6 11 * @note Quaternion.hppを利用されることをお勧めいたします．
Gaku0606 0:c160cac4c370 12 */
Gaku0606 0:c160cac4c370 13 class MadgwickFilter{
Gaku0606 0:c160cac4c370 14
Gaku0606 0:c160cac4c370 15 public:
Gaku0606 0:c160cac4c370 16 /**
Gaku0606 2:e1de76e257f6 17 @bref マドグウィックフィルター(マッジュウィックフィルター)クラスのコンストラクタ
Gaku0606 0:c160cac4c370 18 @param B double型, この値を大きくすると重力の影響を大きく取るようになります．
Gaku0606 0:c160cac4c370 19 @note 引数無しの場合，B = 0.1fが代入されます．
Gaku0606 0:c160cac4c370 20 */
Gaku0606 6:eff5ebc4ea13 21 MadgwickFilter(float B = BETA_DEF);
Gaku0606 0:c160cac4c370 22
Gaku0606 0:c160cac4c370 23 public:
Gaku0606 0:c160cac4c370 24 /**
Gaku0606 0:c160cac4c370 25 @bref MadgwickFilterによって角速度・加速度・地磁気データを統合し，姿勢計算します．
Gaku0606 0:c160cac4c370 26 @param gx,gy,gz 角速度データ，[rad]に変換してから入れてください．
Gaku0606 0:c160cac4c370 27 @param ax,ay,az 加速度データ, 特に規格化は必要ありません
Gaku0606 0:c160cac4c370 28 @param mx,my,mz 地磁気データ, キャリブレーションを確実に行って下さい．
Gaku0606 0:c160cac4c370 29 @note 角速度は[rad]にしてください．この関数は出来るだけ高速に呼び出し続けた方が良いと思います．
Gaku0606 0:c160cac4c370 30 @note 外部でローパスフィルタなどをかけることをお勧めします．
Gaku0606 0:c160cac4c370 31 */
Gaku0606 6:eff5ebc4ea13 32 void MadgwickAHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz);
Gaku0606 0:c160cac4c370 33
Gaku0606 7:c20656d96585 34 /**
Gaku0606 7:c20656d96585 35 @bref MadgwickFilterによって角速度・加速度・地磁気データを統合し，姿勢計算します．
Gaku0606 7:c20656d96585 36 @param gyro 角速度データ，[rad]に変換してから入れてください．
Gaku0606 7:c20656d96585 37 @param acc 加速度データ, 特に規格化は必要ありません
Gaku0606 7:c20656d96585 38 @param mag 地磁気データ, キャリブレーションを確実に行って下さい．
Gaku0606 7:c20656d96585 39 @note 角速度は[rad]にしてください．この関数は出来るだけ高速に呼び出し続けた方が良いと思います．
Gaku0606 7:c20656d96585 40 @note 外部でローパスフィルタなどをかけることをお勧めします．
Gaku0606 7:c20656d96585 41 */
Gaku0606 7:c20656d96585 42 void MadgwickAHRSupdate(float *gyro, float *acc, float *mag);
Gaku0606 7:c20656d96585 43
Gaku0606 0:c160cac4c370 44 /**
Gaku0606 0:c160cac4c370 45 @bref MadgwickFilterを角速度と加速度のみで動かし，姿勢計算を更新します．
Gaku0606 0:c160cac4c370 46 @param gx,gy,gz 角速度データ，[rad]に変換してから入れてください．
Gaku0606 0:c160cac4c370 47 @param ax,ay,az 加速度データ, 特に規格化は必要ありません
Gaku0606 0:c160cac4c370 48 @note 通常の関数でも，地磁気成分を0.0にすればこの関数が呼ばれます．
Gaku0606 0:c160cac4c370 49 */
Gaku0606 6:eff5ebc4ea13 50 void MadgwickAHRSupdateIMU(float gx, float gy, float gz, float ax, float ay, float az);
Gaku0606 0:c160cac4c370 51
Gaku0606 0:c160cac4c370 52 /**
Gaku0606 0:c160cac4c370 53 @bref 姿勢を四元数で取得します．
Gaku0606 0:c160cac4c370 54 @param Q クォータニオンクラスのインスタンスアドレス, w・i・j・kを更新します．
Gaku0606 0:c160cac4c370 55 @note unityに入れる際は軸方向を修正してください．
Gaku0606 0:c160cac4c370 56 */
Gaku0606 0:c160cac4c370 57 void getAttitude(Quaternion *Q);
Gaku0606 0:c160cac4c370 58
Gaku0606 0:c160cac4c370 59 /**
Gaku0606 0:c160cac4c370 60 @bref 姿勢を四元数で取得します．
Gaku0606 0:c160cac4c370 61 @param _q0 実部w, double型, アドレス
Gaku0606 0:c160cac4c370 62 @param _q1 虚部i, double型, アドレス
Gaku0606 0:c160cac4c370 63 @param _q2 虚部j, double型, アドレス
Gaku0606 0:c160cac4c370 64 @param _q3 虚部k, double型, アドレス
Gaku0606 0:c160cac4c370 65 @note unityに入れる際は軸方向を修正してください．
Gaku0606 0:c160cac4c370 66 */
Gaku0606 6:eff5ebc4ea13 67 void getAttitude(float *_q0, float *_q1, float *_q2, float *_q3);
Gaku0606 0:c160cac4c370 68
Gaku0606 0:c160cac4c370 69 /**
Gaku0606 0:c160cac4c370 70 @bref オイラー角で姿勢を取得します．
Gaku0606 0:c160cac4c370 71 @param val ロール，ピッチ，ヨーの順に配列に格納します．３つ以上の要素の配列を入れてください．
Gaku0606 0:c160cac4c370 72 @note 値は[rad]です．[degree]に変換が必要な場合は別途計算して下さい．
Gaku0606 0:c160cac4c370 73 */
Gaku0606 6:eff5ebc4ea13 74 void getEulerAngle(float *val);
Gaku0606 0:c160cac4c370 75 public:
Gaku0606 0:c160cac4c370 76 Timer madgwickTimer;
Gaku0606 0:c160cac4c370 77 Quaternion q;
Gaku0606 6:eff5ebc4ea13 78 float q0,q1,q2,q3;
Gaku0606 6:eff5ebc4ea13 79 float beta;
Gaku0606 0:c160cac4c370 80 };
Gaku0606 0:c160cac4c370 81
Gaku0606 6:eff5ebc4ea13 82 MadgwickFilter::MadgwickFilter(float B){
Gaku0606 0:c160cac4c370 83 q.w = 1.0f;
Gaku0606 0:c160cac4c370 84 q.x = 0.0f;
Gaku0606 0:c160cac4c370 85 q.y = 0.0f;
Gaku0606 0:c160cac4c370 86 q.z = 0.0f;
Gaku0606 0:c160cac4c370 87 beta = B;
Gaku0606 0:c160cac4c370 88 q0 = 1.0f;
Gaku0606 0:c160cac4c370 89 q1 = 0.0f;
Gaku0606 0:c160cac4c370 90 q2 = 0.0f;
Gaku0606 0:c160cac4c370 91 q3 = 0.0f;
Gaku0606 0:c160cac4c370 92 madgwickTimer.start();
Gaku0606 0:c160cac4c370 93 }
Gaku0606 0:c160cac4c370 94
Gaku0606 0:c160cac4c370 95 void MadgwickFilter::getAttitude(Quaternion *Q){
Gaku0606 0:c160cac4c370 96 *Q = q;
Gaku0606 0:c160cac4c370 97 return;
Gaku0606 0:c160cac4c370 98 }
Gaku0606 0:c160cac4c370 99
Gaku0606 0:c160cac4c370 100
Gaku0606 0:c160cac4c370 101
Gaku0606 6:eff5ebc4ea13 102 void MadgwickFilter::getAttitude(float *_q0, float *_q1, float *_q2, float *_q3){
Gaku0606 0:c160cac4c370 103 *_q0 = q0;
Gaku0606 0:c160cac4c370 104 *_q1 = q1;
Gaku0606 0:c160cac4c370 105 *_q2 = q2;
Gaku0606 0:c160cac4c370 106 *_q3 = q3;
Gaku0606 0:c160cac4c370 107 return;
Gaku0606 0:c160cac4c370 108 }
Gaku0606 0:c160cac4c370 109
Gaku0606 0:c160cac4c370 110
Gaku0606 6:eff5ebc4ea13 111 void MadgwickFilter::getEulerAngle(float *val){
Gaku0606 6:eff5ebc4ea13 112 float q0q0 = q0 * q0, q1q1q2q2 = q1 * q1 - q2 * q2, q3q3 = q3 * q3;
Gaku0606 0:c160cac4c370 113 val[0] = (atan2(2.0f * (q0 * q1 + q2 * q3), q0q0 - q1q1q2q2 + q3q3));
Gaku0606 0:c160cac4c370 114 val[1] = (-asin(2.0f * (q1 * q3 - q0 * q2)));
Gaku0606 0:c160cac4c370 115 val[2] = (atan2(2.0f * (q1 * q2 + q0 * q3), q0q0 + q1q1q2q2 - q3q3));
Gaku0606 0:c160cac4c370 116 }
Gaku0606 0:c160cac4c370 117 //---------------------------------------------------------------------------------------------------
Gaku0606 0:c160cac4c370 118 // AHRS algorithm update
Gaku0606 0:c160cac4c370 119
Gaku0606 6:eff5ebc4ea13 120 inline void MadgwickFilter::MadgwickAHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz) {
Gaku0606 5:1e6fecaea25e 121
Gaku0606 6:eff5ebc4ea13 122 static float acc_norm;
Gaku0606 6:eff5ebc4ea13 123 static float deltaT = 0.0f;
Gaku0606 0:c160cac4c370 124 static unsigned int newTime = 0, oldTime = 0;
Gaku0606 6:eff5ebc4ea13 125 static float recipNorm;
Gaku0606 6:eff5ebc4ea13 126 static float s0, s1, s2, s3;
Gaku0606 6:eff5ebc4ea13 127 static float qDot1, qDot2, qDot3, qDot4;
Gaku0606 6:eff5ebc4ea13 128 static float hx, hy;
Gaku0606 6:eff5ebc4ea13 129 static float _2q0mx, _2q0my, _2q0mz, _2q1mx, _2bx, _2bz, _4bx, _4bz, _2q0, _2q1, _2q2, _2q3, _2q0q2, _2q2q3, q0q0, q0q1, q0q2, q0q3, q1q1, q1q2, q1q3, q2q2, q2q3, q3q3;
Gaku0606 0:c160cac4c370 130
Gaku0606 0:c160cac4c370 131 // Use IMU algorithm if magnetometer measurement invalid (avoids NaN in magnetometer normalisation)
Gaku0606 0:c160cac4c370 132 if((mx == 0.0f) && (my == 0.0f) && (mz == 0.0f)) {
Gaku0606 0:c160cac4c370 133 MadgwickAHRSupdateIMU(gx, gy, gz, ax, ay, az);
Gaku0606 0:c160cac4c370 134 return;
Gaku0606 0:c160cac4c370 135 }
Gaku0606 0:c160cac4c370 136
Gaku0606 0:c160cac4c370 137 // Rate of change of quaternion from gyroscope
Gaku0606 0:c160cac4c370 138 qDot1 = 0.5f * (-q1 * gx - q2 * gy - q3 * gz);
Gaku0606 0:c160cac4c370 139 qDot2 = 0.5f * (q0 * gx + q2 * gz - q3 * gy);
Gaku0606 0:c160cac4c370 140 qDot3 = 0.5f * (q0 * gy - q1 * gz + q3 * gx);
Gaku0606 0:c160cac4c370 141 qDot4 = 0.5f * (q0 * gz + q1 * gy - q2 * gx);
Gaku0606 0:c160cac4c370 142
Gaku0606 0:c160cac4c370 143 // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation)
Gaku0606 0:c160cac4c370 144 if(!((ax == 0.0f) && (ay == 0.0f) && (az == 0.0f))) {
Gaku0606 0:c160cac4c370 145
Gaku0606 0:c160cac4c370 146 // Normalise accelerometer measurement
Gaku0606 5:1e6fecaea25e 147 acc_norm = sqrt(ax * ax + ay * ay + az * az);
Gaku0606 6:eff5ebc4ea13 148 recipNorm = 1.0f / acc_norm;
Gaku0606 0:c160cac4c370 149 ax *= recipNorm;
Gaku0606 0:c160cac4c370 150 ay *= recipNorm;
Gaku0606 0:c160cac4c370 151 az *= recipNorm;
Gaku0606 0:c160cac4c370 152
Gaku0606 0:c160cac4c370 153 // Normalise magnetometer measurement
Gaku0606 6:eff5ebc4ea13 154 recipNorm = 1.0f / sqrt(mx * mx + my * my + mz * mz);
Gaku0606 0:c160cac4c370 155 mx *= recipNorm;
Gaku0606 0:c160cac4c370 156 my *= recipNorm;
Gaku0606 0:c160cac4c370 157 mz *= recipNorm;
Gaku0606 0:c160cac4c370 158
Gaku0606 0:c160cac4c370 159 // Auxiliary variables to avoid repeated arithmetic
Gaku0606 0:c160cac4c370 160 _2q0mx = 2.0f * q0 * mx;
Gaku0606 0:c160cac4c370 161 _2q0my = 2.0f * q0 * my;
Gaku0606 0:c160cac4c370 162 _2q0mz = 2.0f * q0 * mz;
Gaku0606 0:c160cac4c370 163 _2q1mx = 2.0f * q1 * mx;
Gaku0606 0:c160cac4c370 164 _2q0 = 2.0f * q0;
Gaku0606 0:c160cac4c370 165 _2q1 = 2.0f * q1;
Gaku0606 0:c160cac4c370 166 _2q2 = 2.0f * q2;
Gaku0606 0:c160cac4c370 167 _2q3 = 2.0f * q3;
Gaku0606 0:c160cac4c370 168 _2q0q2 = 2.0f * q0 * q2;
Gaku0606 0:c160cac4c370 169 _2q2q3 = 2.0f * q2 * q3;
Gaku0606 0:c160cac4c370 170 q0q0 = q0 * q0;
Gaku0606 0:c160cac4c370 171 q0q1 = q0 * q1;
Gaku0606 0:c160cac4c370 172 q0q2 = q0 * q2;
Gaku0606 0:c160cac4c370 173 q0q3 = q0 * q3;
Gaku0606 0:c160cac4c370 174 q1q1 = q1 * q1;
Gaku0606 0:c160cac4c370 175 q1q2 = q1 * q2;
Gaku0606 0:c160cac4c370 176 q1q3 = q1 * q3;
Gaku0606 0:c160cac4c370 177 q2q2 = q2 * q2;
Gaku0606 0:c160cac4c370 178 q2q3 = q2 * q3;
Gaku0606 0:c160cac4c370 179 q3q3 = q3 * q3;
Gaku0606 0:c160cac4c370 180
Gaku0606 0:c160cac4c370 181 // Reference direction of Earth's magnetic field
Gaku0606 0:c160cac4c370 182 hx = mx * q0q0 - _2q0my * q3 + _2q0mz * q2 + mx * q1q1 + _2q1 * my * q2 + _2q1 * mz * q3 - mx * q2q2 - mx * q3q3;
Gaku0606 0:c160cac4c370 183 hy = _2q0mx * q3 + my * q0q0 - _2q0mz * q1 + _2q1mx * q2 - my * q1q1 + my * q2q2 + _2q2 * mz * q3 - my * q3q3;
Gaku0606 0:c160cac4c370 184 _2bx = sqrt(hx * hx + hy * hy);
Gaku0606 0:c160cac4c370 185 _2bz = -_2q0mx * q2 + _2q0my * q1 + mz * q0q0 + _2q1mx * q3 - mz * q1q1 + _2q2 * my * q3 - mz * q2q2 + mz * q3q3;
Gaku0606 0:c160cac4c370 186 _4bx = 2.0f * _2bx;
Gaku0606 0:c160cac4c370 187 _4bz = 2.0f * _2bz;
Gaku0606 0:c160cac4c370 188
Gaku0606 0:c160cac4c370 189 // Gradient decent algorithm corrective step
Gaku0606 0:c160cac4c370 190 s0 = -_2q2 * (2.0f * q1q3 - _2q0q2 - ax) + _2q1 * (2.0f * q0q1 + _2q2q3 - ay) - _2bz * q2 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q3 + _2bz * q1) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q2 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 0:c160cac4c370 191 s1 = _2q3 * (2.0f * q1q3 - _2q0q2 - ax) + _2q0 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q1 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + _2bz * q3 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q2 + _2bz * q0) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q3 - _4bz * q1) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 0:c160cac4c370 192 s2 = -_2q0 * (2.0f * q1q3 - _2q0q2 - ax) + _2q3 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q2 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + (-_4bx * q2 - _2bz * q0) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q1 + _2bz * q3) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q0 - _4bz * q2) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 0:c160cac4c370 193 s3 = _2q1 * (2.0f * q1q3 - _2q0q2 - ax) + _2q2 * (2.0f * q0q1 + _2q2q3 - ay) + (-_4bx * q3 + _2bz * q1) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q0 + _2bz * q2) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q1 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 6:eff5ebc4ea13 194 recipNorm = 1.0f / sqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude
Gaku0606 0:c160cac4c370 195 s0 *= recipNorm;
Gaku0606 0:c160cac4c370 196 s1 *= recipNorm;
Gaku0606 0:c160cac4c370 197 s2 *= recipNorm;
Gaku0606 0:c160cac4c370 198 s3 *= recipNorm;
Gaku0606 0:c160cac4c370 199
Gaku0606 6:eff5ebc4ea13 200 float deltaA = fabs(acc_norm - 1.00f);
Gaku0606 5:1e6fecaea25e 201 //beta = 0.1*exp(-1.0*deltaA*deltaA);
Gaku0606 5:1e6fecaea25e 202 //beta = 0.3*exp(-20.0*deltaA*deltaA);
Gaku0606 7:c20656d96585 203 //beta = beta*exp(-30.0f*deltaA*deltaA);
Gaku0606 5:1e6fecaea25e 204 //printf("%f\r\n", beta);
Gaku0606 6:eff5ebc4ea13 205 //beta = 1.0;
Gaku0606 5:1e6fecaea25e 206 //if(deltaA > 0.3) beta = 0.0;
Gaku0606 0:c160cac4c370 207 // Apply feedback step
Gaku0606 0:c160cac4c370 208 qDot1 -= beta * s0;
Gaku0606 0:c160cac4c370 209 qDot2 -= beta * s1;
Gaku0606 0:c160cac4c370 210 qDot3 -= beta * s2;
Gaku0606 0:c160cac4c370 211 qDot4 -= beta * s3;
Gaku0606 0:c160cac4c370 212 }
Gaku0606 0:c160cac4c370 213
Gaku0606 0:c160cac4c370 214 // Integrate rate of change of quaternion to yield quaternion
Gaku0606 0:c160cac4c370 215 newTime = (unsigned int)madgwickTimer.read_us();
Gaku0606 6:eff5ebc4ea13 216 deltaT = (newTime - oldTime) / 1000000.0f;
Gaku0606 0:c160cac4c370 217 deltaT = fabs(deltaT);
Gaku0606 0:c160cac4c370 218 oldTime = newTime;
Gaku0606 0:c160cac4c370 219
Gaku0606 0:c160cac4c370 220 q0 += qDot1 * deltaT;//(1.0f / sampleFreq);
Gaku0606 0:c160cac4c370 221 q1 += qDot2 * deltaT;//(1.0f / sampleFreq);
Gaku0606 0:c160cac4c370 222 q2 += qDot3 * deltaT;//(1.0f / sampleFreq);
Gaku0606 0:c160cac4c370 223 q3 += qDot4 * deltaT;//(1.0f / sampleFreq);
Gaku0606 0:c160cac4c370 224
Gaku0606 0:c160cac4c370 225 // Normalise quaternion
Gaku0606 6:eff5ebc4ea13 226 recipNorm = 1.0f / sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
Gaku0606 0:c160cac4c370 227 q0 *= recipNorm;
Gaku0606 0:c160cac4c370 228 q1 *= recipNorm;
Gaku0606 0:c160cac4c370 229 q2 *= recipNorm;
Gaku0606 0:c160cac4c370 230 q3 *= recipNorm;
Gaku0606 0:c160cac4c370 231
Gaku0606 0:c160cac4c370 232 q.w = q0;
Gaku0606 0:c160cac4c370 233 q.x = q1;
Gaku0606 0:c160cac4c370 234 q.y = q2;
Gaku0606 0:c160cac4c370 235 q.z = q3;
Gaku0606 0:c160cac4c370 236 }
Gaku0606 0:c160cac4c370 237
Gaku0606 7:c20656d96585 238 inline void MadgwickFilter::MadgwickAHRSupdate(float *gyro, float *acc, float *mag){
Gaku0606 7:c20656d96585 239
Gaku0606 7:c20656d96585 240 static float gx = 0, gy = 0, gz = 0.0f, ax = 0.0f, ay = 0.0f, az = 0.0f, mx = 0.0f, my = 0.0f, mz = 0.0f;
Gaku0606 7:c20656d96585 241 static float acc_norm;
Gaku0606 7:c20656d96585 242 static float deltaT = 0.0f;
Gaku0606 7:c20656d96585 243 static unsigned int newTime = 0, oldTime = 0;
Gaku0606 7:c20656d96585 244 static float recipNorm;
Gaku0606 7:c20656d96585 245 static float s0, s1, s2, s3;
Gaku0606 7:c20656d96585 246 static float qDot1, qDot2, qDot3, qDot4;
Gaku0606 7:c20656d96585 247 static float hx, hy;
Gaku0606 7:c20656d96585 248 static float _2q0mx, _2q0my, _2q0mz, _2q1mx, _2bx, _2bz, _4bx, _4bz, _2q0, _2q1, _2q2, _2q3, _2q0q2, _2q2q3, q0q0, q0q1, q0q2, q0q3, q1q1, q1q2, q1q3, q2q2, q2q3, q3q3;
Gaku0606 7:c20656d96585 249
Gaku0606 7:c20656d96585 250 gx = gyro[0];
Gaku0606 7:c20656d96585 251 gy = gyro[1];
Gaku0606 7:c20656d96585 252 gz = gyro[2];
Gaku0606 7:c20656d96585 253 ax = acc[0];
Gaku0606 7:c20656d96585 254 ay = acc[1];
Gaku0606 7:c20656d96585 255 az = acc[2];
Gaku0606 7:c20656d96585 256 mx = mag[0];
Gaku0606 7:c20656d96585 257 my = mag[1];
Gaku0606 7:c20656d96585 258 mz = mag[2];
Gaku0606 7:c20656d96585 259
Gaku0606 7:c20656d96585 260 // Use IMU algorithm if magnetometer measurement invalid (avoids NaN in magnetometer normalisation)
Gaku0606 7:c20656d96585 261 if((mx == 0.0f) && (my == 0.0f) && (mz == 0.0f)) {
Gaku0606 7:c20656d96585 262 MadgwickAHRSupdateIMU(gx, gy, gz, ax, ay, az);
Gaku0606 7:c20656d96585 263 return;
Gaku0606 7:c20656d96585 264 }
Gaku0606 7:c20656d96585 265
Gaku0606 7:c20656d96585 266 // Rate of change of quaternion from gyroscope
Gaku0606 7:c20656d96585 267 qDot1 = 0.5f * (-q1 * gx - q2 * gy - q3 * gz);
Gaku0606 7:c20656d96585 268 qDot2 = 0.5f * (q0 * gx + q2 * gz - q3 * gy);
Gaku0606 7:c20656d96585 269 qDot3 = 0.5f * (q0 * gy - q1 * gz + q3 * gx);
Gaku0606 7:c20656d96585 270 qDot4 = 0.5f * (q0 * gz + q1 * gy - q2 * gx);
Gaku0606 7:c20656d96585 271
Gaku0606 7:c20656d96585 272 // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation)
Gaku0606 7:c20656d96585 273 if(!((ax == 0.0f) && (ay == 0.0f) && (az == 0.0f))) {
Gaku0606 7:c20656d96585 274
Gaku0606 7:c20656d96585 275 // Normalise accelerometer measurement
Gaku0606 7:c20656d96585 276 acc_norm = sqrt(ax * ax + ay * ay + az * az);
Gaku0606 7:c20656d96585 277 recipNorm = 1.0f / acc_norm;
Gaku0606 7:c20656d96585 278 ax *= recipNorm;
Gaku0606 7:c20656d96585 279 ay *= recipNorm;
Gaku0606 7:c20656d96585 280 az *= recipNorm;
Gaku0606 7:c20656d96585 281
Gaku0606 7:c20656d96585 282 // Normalise magnetometer measurement
Gaku0606 7:c20656d96585 283 recipNorm = 1.0f / sqrt(mx * mx + my * my + mz * mz);
Gaku0606 7:c20656d96585 284 mx *= recipNorm;
Gaku0606 7:c20656d96585 285 my *= recipNorm;
Gaku0606 7:c20656d96585 286 mz *= recipNorm;
Gaku0606 7:c20656d96585 287
Gaku0606 7:c20656d96585 288 // Auxiliary variables to avoid repeated arithmetic
Gaku0606 7:c20656d96585 289 _2q0mx = 2.0f * q0 * mx;
Gaku0606 7:c20656d96585 290 _2q0my = 2.0f * q0 * my;
Gaku0606 7:c20656d96585 291 _2q0mz = 2.0f * q0 * mz;
Gaku0606 7:c20656d96585 292 _2q1mx = 2.0f * q1 * mx;
Gaku0606 7:c20656d96585 293 _2q0 = 2.0f * q0;
Gaku0606 7:c20656d96585 294 _2q1 = 2.0f * q1;
Gaku0606 7:c20656d96585 295 _2q2 = 2.0f * q2;
Gaku0606 7:c20656d96585 296 _2q3 = 2.0f * q3;
Gaku0606 7:c20656d96585 297 _2q0q2 = 2.0f * q0 * q2;
Gaku0606 7:c20656d96585 298 _2q2q3 = 2.0f * q2 * q3;
Gaku0606 7:c20656d96585 299 q0q0 = q0 * q0;
Gaku0606 7:c20656d96585 300 q0q1 = q0 * q1;
Gaku0606 7:c20656d96585 301 q0q2 = q0 * q2;
Gaku0606 7:c20656d96585 302 q0q3 = q0 * q3;
Gaku0606 7:c20656d96585 303 q1q1 = q1 * q1;
Gaku0606 7:c20656d96585 304 q1q2 = q1 * q2;
Gaku0606 7:c20656d96585 305 q1q3 = q1 * q3;
Gaku0606 7:c20656d96585 306 q2q2 = q2 * q2;
Gaku0606 7:c20656d96585 307 q2q3 = q2 * q3;
Gaku0606 7:c20656d96585 308 q3q3 = q3 * q3;
Gaku0606 7:c20656d96585 309
Gaku0606 7:c20656d96585 310 // Reference direction of Earth's magnetic field
Gaku0606 7:c20656d96585 311 hx = mx * q0q0 - _2q0my * q3 + _2q0mz * q2 + mx * q1q1 + _2q1 * my * q2 + _2q1 * mz * q3 - mx * q2q2 - mx * q3q3;
Gaku0606 7:c20656d96585 312 hy = _2q0mx * q3 + my * q0q0 - _2q0mz * q1 + _2q1mx * q2 - my * q1q1 + my * q2q2 + _2q2 * mz * q3 - my * q3q3;
Gaku0606 7:c20656d96585 313 _2bx = sqrt(hx * hx + hy * hy);
Gaku0606 7:c20656d96585 314 _2bz = -_2q0mx * q2 + _2q0my * q1 + mz * q0q0 + _2q1mx * q3 - mz * q1q1 + _2q2 * my * q3 - mz * q2q2 + mz * q3q3;
Gaku0606 7:c20656d96585 315 _4bx = 2.0f * _2bx;
Gaku0606 7:c20656d96585 316 _4bz = 2.0f * _2bz;
Gaku0606 7:c20656d96585 317
Gaku0606 7:c20656d96585 318 // Gradient decent algorithm corrective step
Gaku0606 7:c20656d96585 319 s0 = -_2q2 * (2.0f * q1q3 - _2q0q2 - ax) + _2q1 * (2.0f * q0q1 + _2q2q3 - ay) - _2bz * q2 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q3 + _2bz * q1) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q2 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 7:c20656d96585 320 s1 = _2q3 * (2.0f * q1q3 - _2q0q2 - ax) + _2q0 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q1 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + _2bz * q3 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q2 + _2bz * q0) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q3 - _4bz * q1) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 7:c20656d96585 321 s2 = -_2q0 * (2.0f * q1q3 - _2q0q2 - ax) + _2q3 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q2 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + (-_4bx * q2 - _2bz * q0) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q1 + _2bz * q3) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q0 - _4bz * q2) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 7:c20656d96585 322 s3 = _2q1 * (2.0f * q1q3 - _2q0q2 - ax) + _2q2 * (2.0f * q0q1 + _2q2q3 - ay) + (-_4bx * q3 + _2bz * q1) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q0 + _2bz * q2) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q1 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
Gaku0606 7:c20656d96585 323 recipNorm = 1.0f / sqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude
Gaku0606 7:c20656d96585 324 s0 *= recipNorm;
Gaku0606 7:c20656d96585 325 s1 *= recipNorm;
Gaku0606 7:c20656d96585 326 s2 *= recipNorm;
Gaku0606 7:c20656d96585 327 s3 *= recipNorm;
Gaku0606 7:c20656d96585 328
Gaku0606 7:c20656d96585 329 float deltaA = fabs(acc_norm - 1.00f);
Gaku0606 7:c20656d96585 330 //beta = 0.1*exp(-1.0*deltaA*deltaA);
Gaku0606 7:c20656d96585 331 //beta = 0.3*exp(-20.0*deltaA*deltaA);
Gaku0606 7:c20656d96585 332 //beta = beta*exp(-30.0f*deltaA*deltaA);
Gaku0606 7:c20656d96585 333 //printf("%f\r\n", beta);
Gaku0606 7:c20656d96585 334 //beta = 1.0;
Gaku0606 7:c20656d96585 335 //if(deltaA > 0.3) beta = 0.0;
Gaku0606 7:c20656d96585 336 // Apply feedback step
Gaku0606 7:c20656d96585 337 qDot1 -= beta * s0;
Gaku0606 7:c20656d96585 338 qDot2 -= beta * s1;
Gaku0606 7:c20656d96585 339 qDot3 -= beta * s2;
Gaku0606 7:c20656d96585 340 qDot4 -= beta * s3;
Gaku0606 7:c20656d96585 341 }
Gaku0606 7:c20656d96585 342
Gaku0606 7:c20656d96585 343 // Integrate rate of change of quaternion to yield quaternion
Gaku0606 7:c20656d96585 344 newTime = (unsigned int)madgwickTimer.read_us();
Gaku0606 7:c20656d96585 345 deltaT = (newTime - oldTime) / 1000000.0f;
Gaku0606 7:c20656d96585 346 deltaT = fabs(deltaT);
Gaku0606 7:c20656d96585 347 oldTime = newTime;
Gaku0606 7:c20656d96585 348
Gaku0606 7:c20656d96585 349 q0 += qDot1 * deltaT;//(1.0f / sampleFreq);
Gaku0606 7:c20656d96585 350 q1 += qDot2 * deltaT;//(1.0f / sampleFreq);
Gaku0606 7:c20656d96585 351 q2 += qDot3 * deltaT;//(1.0f / sampleFreq);
Gaku0606 7:c20656d96585 352 q3 += qDot4 * deltaT;//(1.0f / sampleFreq);
Gaku0606 7:c20656d96585 353
Gaku0606 7:c20656d96585 354 // Normalise quaternion
Gaku0606 7:c20656d96585 355 recipNorm = 1.0f / sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
Gaku0606 7:c20656d96585 356 q0 *= recipNorm;
Gaku0606 7:c20656d96585 357 q1 *= recipNorm;
Gaku0606 7:c20656d96585 358 q2 *= recipNorm;
Gaku0606 7:c20656d96585 359 q3 *= recipNorm;
Gaku0606 7:c20656d96585 360
Gaku0606 7:c20656d96585 361 q.w = q0;
Gaku0606 7:c20656d96585 362 q.x = q1;
Gaku0606 7:c20656d96585 363 q.y = q2;
Gaku0606 7:c20656d96585 364 q.z = q3;
Gaku0606 7:c20656d96585 365 }
Gaku0606 7:c20656d96585 366
Gaku0606 0:c160cac4c370 367 //---------------------------------------------------------------------------------------------------
Gaku0606 0:c160cac4c370 368 // IMU algorithm update
Gaku0606 0:c160cac4c370 369
Gaku0606 6:eff5ebc4ea13 370 inline void MadgwickFilter::MadgwickAHRSupdateIMU(float gx, float gy, float gz, float ax, float ay, float az) {
Gaku0606 6:eff5ebc4ea13 371 static float deltaT = 0;
Gaku0606 0:c160cac4c370 372 static unsigned int newTime = 0, oldTime = 0;
Gaku0606 6:eff5ebc4ea13 373 static float recipNorm;
Gaku0606 6:eff5ebc4ea13 374 static float s0, s1, s2, s3;
Gaku0606 6:eff5ebc4ea13 375 static float qDot1, qDot2, qDot3, qDot4;
Gaku0606 6:eff5ebc4ea13 376 static float _2q0, _2q1, _2q2, _2q3, _4q0, _4q1, _4q2 ,_8q1, _8q2, q0q0, q1q1, q2q2, q3q3;
Gaku0606 6:eff5ebc4ea13 377 static float acc_norm;
Gaku0606 0:c160cac4c370 378
Gaku0606 0:c160cac4c370 379 // Rate of change of quaternion from gyroscope
Gaku0606 0:c160cac4c370 380 qDot1 = 0.5f * (-q1 * gx - q2 * gy - q3 * gz);
Gaku0606 0:c160cac4c370 381 qDot2 = 0.5f * (q0 * gx + q2 * gz - q3 * gy);
Gaku0606 0:c160cac4c370 382 qDot3 = 0.5f * (q0 * gy - q1 * gz + q3 * gx);
Gaku0606 0:c160cac4c370 383 qDot4 = 0.5f * (q0 * gz + q1 * gy - q2 * gx);
Gaku0606 0:c160cac4c370 384
Gaku0606 0:c160cac4c370 385 // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation)
Gaku0606 0:c160cac4c370 386 if(!((ax == 0.0f) && (ay == 0.0f) && (az == 0.0f))) {
Gaku0606 0:c160cac4c370 387
Gaku0606 0:c160cac4c370 388 // Normalise accelerometer measurement
Gaku0606 5:1e6fecaea25e 389 acc_norm = sqrt(ax * ax + ay * ay + az * az);
Gaku0606 6:eff5ebc4ea13 390 recipNorm = 1.0f / acc_norm;
Gaku0606 0:c160cac4c370 391 ax *= recipNorm;
Gaku0606 0:c160cac4c370 392 ay *= recipNorm;
Gaku0606 0:c160cac4c370 393 az *= recipNorm;
Gaku0606 0:c160cac4c370 394
Gaku0606 0:c160cac4c370 395 // Auxiliary variables to avoid repeated arithmetic
Gaku0606 0:c160cac4c370 396 _2q0 = 2.0f * q0;
Gaku0606 0:c160cac4c370 397 _2q1 = 2.0f * q1;
Gaku0606 0:c160cac4c370 398 _2q2 = 2.0f * q2;
Gaku0606 0:c160cac4c370 399 _2q3 = 2.0f * q3;
Gaku0606 0:c160cac4c370 400 _4q0 = 4.0f * q0;
Gaku0606 0:c160cac4c370 401 _4q1 = 4.0f * q1;
Gaku0606 0:c160cac4c370 402 _4q2 = 4.0f * q2;
Gaku0606 0:c160cac4c370 403 _8q1 = 8.0f * q1;
Gaku0606 0:c160cac4c370 404 _8q2 = 8.0f * q2;
Gaku0606 0:c160cac4c370 405 q0q0 = q0 * q0;
Gaku0606 0:c160cac4c370 406 q1q1 = q1 * q1;
Gaku0606 0:c160cac4c370 407 q2q2 = q2 * q2;
Gaku0606 0:c160cac4c370 408 q3q3 = q3 * q3;
Gaku0606 0:c160cac4c370 409
Gaku0606 0:c160cac4c370 410 // Gradient decent algorithm corrective step
Gaku0606 0:c160cac4c370 411 s0 = _4q0 * q2q2 + _2q2 * ax + _4q0 * q1q1 - _2q1 * ay;
Gaku0606 0:c160cac4c370 412 s1 = _4q1 * q3q3 - _2q3 * ax + 4.0f * q0q0 * q1 - _2q0 * ay - _4q1 + _8q1 * q1q1 + _8q1 * q2q2 + _4q1 * az;
Gaku0606 0:c160cac4c370 413 s2 = 4.0f * q0q0 * q2 + _2q0 * ax + _4q2 * q3q3 - _2q3 * ay - _4q2 + _8q2 * q1q1 + _8q2 * q2q2 + _4q2 * az;
Gaku0606 0:c160cac4c370 414 s3 = 4.0f * q1q1 * q3 - _2q1 * ax + 4.0f * q2q2 * q3 - _2q2 * ay;
Gaku0606 6:eff5ebc4ea13 415 recipNorm = 1.0f / sqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude
Gaku0606 0:c160cac4c370 416 s0 *= recipNorm;
Gaku0606 0:c160cac4c370 417 s1 *= recipNorm;
Gaku0606 0:c160cac4c370 418 s2 *= recipNorm;
Gaku0606 0:c160cac4c370 419 s3 *= recipNorm;
Gaku0606 0:c160cac4c370 420
Gaku0606 0:c160cac4c370 421 // Apply feedback step
Gaku0606 6:eff5ebc4ea13 422 static float deltaA;
Gaku0606 6:eff5ebc4ea13 423 deltaA = fabs(acc_norm - 1.00f);
Gaku0606 5:1e6fecaea25e 424 //beta = 0.5*exp(-20.0*deltaA*deltaA);
Gaku0606 6:eff5ebc4ea13 425 if(deltaA > 0.3f) beta = 0.0f;
Gaku0606 6:eff5ebc4ea13 426 else beta = 0.1f;
Gaku0606 0:c160cac4c370 427 qDot1 -= beta * s0;
Gaku0606 0:c160cac4c370 428 qDot2 -= beta * s1;
Gaku0606 0:c160cac4c370 429 qDot3 -= beta * s2;
Gaku0606 0:c160cac4c370 430 qDot4 -= beta * s3;
Gaku0606 0:c160cac4c370 431 }
Gaku0606 0:c160cac4c370 432
Gaku0606 0:c160cac4c370 433 // Integrate rate of change of quaternion to yield quaternion
Gaku0606 0:c160cac4c370 434 newTime = (unsigned int)madgwickTimer.read_us();
Gaku0606 6:eff5ebc4ea13 435 deltaT = (newTime - oldTime) / 1000000.0f;
Gaku0606 0:c160cac4c370 436 deltaT = fabs(deltaT);
Gaku0606 0:c160cac4c370 437 oldTime = newTime;
Gaku0606 0:c160cac4c370 438 q0 += qDot1 * deltaT;;
Gaku0606 0:c160cac4c370 439 q1 += qDot2 * deltaT;;
Gaku0606 0:c160cac4c370 440 q2 += qDot3 * deltaT;;
Gaku0606 0:c160cac4c370 441 q3 += qDot4 * deltaT;;
Gaku0606 0:c160cac4c370 442
Gaku0606 0:c160cac4c370 443 // Normalise quaternion
Gaku0606 6:eff5ebc4ea13 444 recipNorm = 1.0f / sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
Gaku0606 0:c160cac4c370 445 q0 *= recipNorm;
Gaku0606 0:c160cac4c370 446 q1 *= recipNorm;
Gaku0606 0:c160cac4c370 447 q2 *= recipNorm;
Gaku0606 0:c160cac4c370 448 q3 *= recipNorm;
Gaku0606 0:c160cac4c370 449
Gaku0606 0:c160cac4c370 450 q.w = q0;
Gaku0606 0:c160cac4c370 451 q.x = q1;
Gaku0606 0:c160cac4c370 452 q.y = q2;
Gaku0606 0:c160cac4c370 453 q.z = q3;
Gaku0606 0:c160cac4c370 454 }
Gaku0606 0:c160cac4c370 455
Gaku0606 0:c160cac4c370 456
Gaku0606 0:c160cac4c370 457 #endif