Madgewick Filter to get attitude from IMU or MARG. Confirmed IMU ver works well.
Dependents: NineIMUAttitude_MadgwickFilter
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
- Child:
- 8:72c013425ecc
kkk
Who changed what in which revision?
User | Revision | Line number | New 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 |