Bremen Team - Hangar
Implemented first Hangar-Service
Dependencies: CalibrateMagneto QuaternionMath
Fork of
SML2
by 
TobyRich GmbH
SensorFusion.cpp@46:fd5a62296b12, 2015-05-27 (annotated)
- Committer:
- pvaibhav
- Date:
- Wed May 27 13:01:43 2015 +0000
- Revision:
- 46:fd5a62296b12
- Parent:
- 43:6251c0169f4f
Code reformatted
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| pvaibhav | 15:4488660e1a3b | 1 | #include "SensorFusion.h" |
| pvaibhav | 15:4488660e1a3b | 2 | |
| pvaibhav | 15:4488660e1a3b | 3 | #define DEBUG "SensorFusion" |
| pvaibhav | 15:4488660e1a3b | 4 | #include "Logger.h" |
| pvaibhav | 15:4488660e1a3b | 5 | |
| pvaibhav | 34:01dec68de3ed | 6 | #include "Utils.h" |
| pvaibhav | 34:01dec68de3ed | 7 | |
| pvaibhav | 40:8e852115fe55 | 8 | SensorFusion6::SensorFusion6(I2C &i2c) : |
| pvaibhav | 40:8e852115fe55 | 9 | SensorFusion(), |
| pvaibhav | 40:8e852115fe55 | 10 | accel(i2c), |
| pvaibhav | 40:8e852115fe55 | 11 | gyro(i2c), |
| pvaibhav | 40:8e852115fe55 | 12 | deltat(0.010), // seconds |
| pvaibhav | 43:6251c0169f4f | 13 | beta(50), |
| pvaibhav | 43:6251c0169f4f | 14 | lowpassX(0.96), |
| pvaibhav | 43:6251c0169f4f | 15 | lowpassY(0.96), |
| pvaibhav | 43:6251c0169f4f | 16 | lowpassZ(0.96) |
| pvaibhav | 15:4488660e1a3b | 17 | { |
| pvaibhav | 40:8e852115fe55 | 18 | gyro.setDelegate(*this); |
| pvaibhav | 20:503cbe360419 | 19 | } |
| pvaibhav | 20:503cbe360419 | 20 | |
| pvaibhav | 40:8e852115fe55 | 21 | bool SensorFusion6::start() |
| pvaibhav | 20:503cbe360419 | 22 | { |
| pvaibhav | 40:8e852115fe55 | 23 | lowpassX.reset(); |
| pvaibhav | 40:8e852115fe55 | 24 | lowpassY.reset(); |
| pvaibhav | 40:8e852115fe55 | 25 | lowpassZ.reset(); |
| pvaibhav | 46:fd5a62296b12 | 26 | |
| pvaibhav | 15:4488660e1a3b | 27 | accel.powerOn(); |
| pvaibhav | 15:4488660e1a3b | 28 | accel.start(); |
| pvaibhav | 46:fd5a62296b12 | 29 | |
| pvaibhav | 15:4488660e1a3b | 30 | // Since everything is synced to gyro interrupt, start it last |
| pvaibhav | 15:4488660e1a3b | 31 | gyro.powerOn(); |
| pvaibhav | 15:4488660e1a3b | 32 | gyro.start(); |
| pvaibhav | 46:fd5a62296b12 | 33 | |
| pvaibhav | 15:4488660e1a3b | 34 | return true; |
| pvaibhav | 15:4488660e1a3b | 35 | } |
| pvaibhav | 15:4488660e1a3b | 36 | |
| pvaibhav | 40:8e852115fe55 | 37 | void SensorFusion6::stop() |
| pvaibhav | 15:4488660e1a3b | 38 | { |
| pvaibhav | 15:4488660e1a3b | 39 | gyro.stop(); |
| pvaibhav | 40:8e852115fe55 | 40 | gyro.powerOff(); |
| pvaibhav | 46:fd5a62296b12 | 41 | |
| pvaibhav | 15:4488660e1a3b | 42 | accel.stop(); |
| pvaibhav | 15:4488660e1a3b | 43 | accel.powerOff(); |
| pvaibhav | 15:4488660e1a3b | 44 | } |
| pvaibhav | 15:4488660e1a3b | 45 | |
| pvaibhav | 15:4488660e1a3b | 46 | static float const deg_to_radian = 0.0174532925f; |
| pvaibhav | 15:4488660e1a3b | 47 | |
| pvaibhav | 40:8e852115fe55 | 48 | void SensorFusion6::sensorUpdate(Vector3 gyro_degrees) |
| pvaibhav | 46:fd5a62296b12 | 49 | { |
| pvaibhav | 15:4488660e1a3b | 50 | Vector3 const gyro_reading = gyro_degrees * deg_to_radian; |
| pvaibhav | 15:4488660e1a3b | 51 | Vector3 const accel_reading = accel.read(); |
| pvaibhav | 40:8e852115fe55 | 52 | Vector3 const filtered_accel = Vector3( lowpassX.filter(accel_reading.x), |
| pvaibhav | 40:8e852115fe55 | 53 | lowpassY.filter(accel_reading.y), |
| pvaibhav | 40:8e852115fe55 | 54 | lowpassZ.filter(accel_reading.z)); |
| pvaibhav | 15:4488660e1a3b | 55 | |
| pvaibhav | 40:8e852115fe55 | 56 | updateFilter( filtered_accel.x, filtered_accel.y, filtered_accel.z, |
| pvaibhav | 46:fd5a62296b12 | 57 | gyro_reading.x, gyro_reading.y, gyro_reading.z); |
| pvaibhav | 46:fd5a62296b12 | 58 | |
| pvaibhav | 40:8e852115fe55 | 59 | delegate->sensorTick(deltat, q.getEulerAngles(), filtered_accel, accel_reading, gyro_degrees, q); |
| pvaibhav | 34:01dec68de3ed | 60 | } |
| pvaibhav | 34:01dec68de3ed | 61 | |
| pvaibhav | 40:8e852115fe55 | 62 | void SensorFusion6::updateFilter(float ax, float ay, float az, float gx, float gy, float gz) |
| pvaibhav | 35:fb6e4601adf3 | 63 | { |
| pvaibhav | 35:fb6e4601adf3 | 64 | float q0 = q.w, q1 = q.v.x, q2 = q.v.y, q3 = q.v.z; // short name local variable for readability |
| pvaibhav | 46:fd5a62296b12 | 65 | |
| pvaibhav | 35:fb6e4601adf3 | 66 | float recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 67 | float s0, s1, s2, s3; |
| pvaibhav | 35:fb6e4601adf3 | 68 | float qDot1, qDot2, qDot3, qDot4; |
| pvaibhav | 35:fb6e4601adf3 | 69 | float _2q0, _2q1, _2q2, _2q3, _4q0, _4q1, _4q2 ,_8q1, _8q2, q0q0, q1q1, q2q2, q3q3; |
| pvaibhav | 35:fb6e4601adf3 | 70 | |
| pvaibhav | 35:fb6e4601adf3 | 71 | // Rate of change of quaternion from gyroscope |
| pvaibhav | 35:fb6e4601adf3 | 72 | qDot1 = 0.5 * (-q1 * gx - q2 * gy - q3 * gz); |
| pvaibhav | 35:fb6e4601adf3 | 73 | qDot2 = 0.5 * (q0 * gx + q2 * gz - q3 * gy); |
| pvaibhav | 35:fb6e4601adf3 | 74 | qDot3 = 0.5 * (q0 * gy - q1 * gz + q3 * gx); |
| pvaibhav | 35:fb6e4601adf3 | 75 | qDot4 = 0.5 * (q0 * gz + q1 * gy - q2 * gx); |
| pvaibhav | 35:fb6e4601adf3 | 76 | |
| pvaibhav | 35:fb6e4601adf3 | 77 | // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation) |
| pvaibhav | 35:fb6e4601adf3 | 78 | if(!((ax == 0.0) && (ay == 0.0) && (az == 0.0))) { |
| pvaibhav | 35:fb6e4601adf3 | 79 | |
| pvaibhav | 35:fb6e4601adf3 | 80 | // Normalise accelerometer measurement |
| pvaibhav | 35:fb6e4601adf3 | 81 | recipNorm = 1.0 / sqrt(ax * ax + ay * ay + az * az); |
| pvaibhav | 35:fb6e4601adf3 | 82 | ax *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 83 | ay *= recipNorm; |
| pvaibhav | 46:fd5a62296b12 | 84 | az *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 85 | |
| pvaibhav | 35:fb6e4601adf3 | 86 | // Auxiliary variables to avoid repeated arithmetic |
| pvaibhav | 35:fb6e4601adf3 | 87 | _2q0 = 2.0 * q0; |
| pvaibhav | 35:fb6e4601adf3 | 88 | _2q1 = 2.0 * q1; |
| pvaibhav | 35:fb6e4601adf3 | 89 | _2q2 = 2.0 * q2; |
| pvaibhav | 35:fb6e4601adf3 | 90 | _2q3 = 2.0 * q3; |
| pvaibhav | 35:fb6e4601adf3 | 91 | _4q0 = 4.0 * q0; |
| pvaibhav | 35:fb6e4601adf3 | 92 | _4q1 = 4.0 * q1; |
| pvaibhav | 35:fb6e4601adf3 | 93 | _4q2 = 4.0 * q2; |
| pvaibhav | 35:fb6e4601adf3 | 94 | _8q1 = 8.0 * q1; |
| pvaibhav | 35:fb6e4601adf3 | 95 | _8q2 = 8.0 * q2; |
| pvaibhav | 35:fb6e4601adf3 | 96 | q0q0 = q0 * q0; |
| pvaibhav | 35:fb6e4601adf3 | 97 | q1q1 = q1 * q1; |
| pvaibhav | 35:fb6e4601adf3 | 98 | q2q2 = q2 * q2; |
| pvaibhav | 35:fb6e4601adf3 | 99 | q3q3 = q3 * q3; |
| pvaibhav | 35:fb6e4601adf3 | 100 | |
| pvaibhav | 35:fb6e4601adf3 | 101 | // Gradient decent algorithm corrective step |
| pvaibhav | 35:fb6e4601adf3 | 102 | s0 = _4q0 * q2q2 + _2q2 * ax + _4q0 * q1q1 - _2q1 * ay; |
| pvaibhav | 35:fb6e4601adf3 | 103 | s1 = _4q1 * q3q3 - _2q3 * ax + 4.0 * q0q0 * q1 - _2q0 * ay - _4q1 + _8q1 * q1q1 + _8q1 * q2q2 + _4q1 * az; |
| pvaibhav | 35:fb6e4601adf3 | 104 | s2 = 4.0 * q0q0 * q2 + _2q0 * ax + _4q2 * q3q3 - _2q3 * ay - _4q2 + _8q2 * q1q1 + _8q2 * q2q2 + _4q2 * az; |
| pvaibhav | 35:fb6e4601adf3 | 105 | s3 = 4.0 * q1q1 * q3 - _2q1 * ax + 4.0 * q2q2 * q3 - _2q2 * ay; |
| pvaibhav | 35:fb6e4601adf3 | 106 | recipNorm = 1.0 / sqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude |
| pvaibhav | 35:fb6e4601adf3 | 107 | s0 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 108 | s1 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 109 | s2 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 110 | s3 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 111 | |
| pvaibhav | 35:fb6e4601adf3 | 112 | // Apply feedback step |
| pvaibhav | 35:fb6e4601adf3 | 113 | qDot1 -= beta * s0; |
| pvaibhav | 35:fb6e4601adf3 | 114 | qDot2 -= beta * s1; |
| pvaibhav | 35:fb6e4601adf3 | 115 | qDot3 -= beta * s2; |
| pvaibhav | 35:fb6e4601adf3 | 116 | qDot4 -= beta * s3; |
| pvaibhav | 35:fb6e4601adf3 | 117 | } |
| pvaibhav | 35:fb6e4601adf3 | 118 | |
| pvaibhav | 35:fb6e4601adf3 | 119 | // Integrate rate of change of quaternion to yield quaternion |
| pvaibhav | 35:fb6e4601adf3 | 120 | q0 += qDot1 * deltat; |
| pvaibhav | 35:fb6e4601adf3 | 121 | q1 += qDot2 * deltat; |
| pvaibhav | 35:fb6e4601adf3 | 122 | q2 += qDot3 * deltat; |
| pvaibhav | 35:fb6e4601adf3 | 123 | q3 += qDot4 * deltat; |
| pvaibhav | 35:fb6e4601adf3 | 124 | |
| pvaibhav | 35:fb6e4601adf3 | 125 | // Normalise quaternion |
| pvaibhav | 35:fb6e4601adf3 | 126 | recipNorm = 1.0 / sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3); |
| pvaibhav | 35:fb6e4601adf3 | 127 | q0 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 128 | q1 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 129 | q2 *= recipNorm; |
| pvaibhav | 35:fb6e4601adf3 | 130 | q3 *= recipNorm; |
| pvaibhav | 46:fd5a62296b12 | 131 | |
| pvaibhav | 35:fb6e4601adf3 | 132 | // return |
| pvaibhav | 35:fb6e4601adf3 | 133 | q.w = q0; |
| pvaibhav | 35:fb6e4601adf3 | 134 | q.v.x = q1; |
| pvaibhav | 35:fb6e4601adf3 | 135 | q.v.y = q2; |
| pvaibhav | 35:fb6e4601adf3 | 136 | q.v.z = q3; |
| pvaibhav | 35:fb6e4601adf3 | 137 | } |
| pvaibhav | 35:fb6e4601adf3 | 138 | |
| pvaibhav | 43:6251c0169f4f | 139 | SensorFusion9::SensorFusion9(I2C &i2c) : SensorFusion6(i2c), magneto(i2c) |
| pvaibhav | 43:6251c0169f4f | 140 | { |
| pvaibhav | 43:6251c0169f4f | 141 | gyro.setDelegate(*this); |
| pvaibhav | 43:6251c0169f4f | 142 | } |
| pvaibhav | 43:6251c0169f4f | 143 | |
| pvaibhav | 43:6251c0169f4f | 144 | bool SensorFusion9::start() |
| pvaibhav | 43:6251c0169f4f | 145 | { |
| pvaibhav | 43:6251c0169f4f | 146 | magneto.powerOn(); |
| pvaibhav | 43:6251c0169f4f | 147 | magneto.start(); |
| pvaibhav | 46:fd5a62296b12 | 148 | |
| pvaibhav | 43:6251c0169f4f | 149 | return SensorFusion6::start(); |
| pvaibhav | 43:6251c0169f4f | 150 | } |
| pvaibhav | 43:6251c0169f4f | 151 | |
| pvaibhav | 43:6251c0169f4f | 152 | void SensorFusion9::stop() |
| pvaibhav | 43:6251c0169f4f | 153 | { |
| pvaibhav | 43:6251c0169f4f | 154 | SensorFusion6::stop(); |
| pvaibhav | 43:6251c0169f4f | 155 | magneto.stop(); |
| pvaibhav | 43:6251c0169f4f | 156 | magneto.powerOff(); |
| pvaibhav | 43:6251c0169f4f | 157 | } |
| pvaibhav | 43:6251c0169f4f | 158 | |
| pvaibhav | 43:6251c0169f4f | 159 | void SensorFusion9::sensorUpdate(Vector3 gyro_degrees) |
| pvaibhav | 43:6251c0169f4f | 160 | { |
| pvaibhav | 43:6251c0169f4f | 161 | Vector3 const gyro_reading = gyro_degrees * deg_to_radian; |
| pvaibhav | 43:6251c0169f4f | 162 | Vector3 const accel_reading = accel.read(); |
| pvaibhav | 43:6251c0169f4f | 163 | Vector3 const magneto_reading = magneto.read(); |
| pvaibhav | 46:fd5a62296b12 | 164 | |
| pvaibhav | 43:6251c0169f4f | 165 | Vector3 const filtered_accel = Vector3( lowpassX.filter(accel_reading.x), |
| pvaibhav | 43:6251c0169f4f | 166 | lowpassY.filter(accel_reading.y), |
| pvaibhav | 43:6251c0169f4f | 167 | lowpassZ.filter(accel_reading.z)); |
| pvaibhav | 43:6251c0169f4f | 168 | |
| pvaibhav | 43:6251c0169f4f | 169 | updateFilter( filtered_accel.x, filtered_accel.y, filtered_accel.z, |
| pvaibhav | 46:fd5a62296b12 | 170 | gyro_reading.x, gyro_reading.y, gyro_reading.z, |
| pvaibhav | 46:fd5a62296b12 | 171 | magneto_reading.x, magneto_reading.y, magneto_reading.z); |
| pvaibhav | 46:fd5a62296b12 | 172 | |
| pvaibhav | 43:6251c0169f4f | 173 | delegate->sensorTick(deltat, q.getEulerAngles(), filtered_accel, magneto_reading, gyro_degrees, q); |
| pvaibhav | 43:6251c0169f4f | 174 | } |
| pvaibhav | 43:6251c0169f4f | 175 | |
| pvaibhav | 40:8e852115fe55 | 176 | void SensorFusion9::updateFilter(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) |
| pvaibhav | 15:4488660e1a3b | 177 | { |
| pvaibhav | 15:4488660e1a3b | 178 | float q1 = q.w, q2 = q.v.x, q3 = q.v.y, q4 = q.v.z; // short name local variable for readability |
| pvaibhav | 15:4488660e1a3b | 179 | float norm; |
| pvaibhav | 15:4488660e1a3b | 180 | float s1, s2, s3, s4; |
| pvaibhav | 15:4488660e1a3b | 181 | |
| pvaibhav | 15:4488660e1a3b | 182 | // Auxiliary variables to avoid repeated arithmetic |
| pvaibhav | 15:4488660e1a3b | 183 | const float _2q1 = 2.0f * q1; |
| pvaibhav | 15:4488660e1a3b | 184 | const float _2q2 = 2.0f * q2; |
| pvaibhav | 15:4488660e1a3b | 185 | const float _2q3 = 2.0f * q3; |
| pvaibhav | 15:4488660e1a3b | 186 | const float _2q4 = 2.0f * q4; |
| pvaibhav | 15:4488660e1a3b | 187 | const float _2q1q3 = 2.0f * q1 * q3; |
| pvaibhav | 15:4488660e1a3b | 188 | const float _2q3q4 = 2.0f * q3 * q4; |
| pvaibhav | 15:4488660e1a3b | 189 | const float q1q1 = q1 * q1; |
| pvaibhav | 15:4488660e1a3b | 190 | const float q1q2 = q1 * q2; |
| pvaibhav | 15:4488660e1a3b | 191 | const float q1q3 = q1 * q3; |
| pvaibhav | 15:4488660e1a3b | 192 | const float q1q4 = q1 * q4; |
| pvaibhav | 15:4488660e1a3b | 193 | const float q2q2 = q2 * q2; |
| pvaibhav | 15:4488660e1a3b | 194 | const float q2q3 = q2 * q3; |
| pvaibhav | 15:4488660e1a3b | 195 | const float q2q4 = q2 * q4; |
| pvaibhav | 15:4488660e1a3b | 196 | const float q3q3 = q3 * q3; |
| pvaibhav | 15:4488660e1a3b | 197 | const float q3q4 = q3 * q4; |
| pvaibhav | 15:4488660e1a3b | 198 | const float q4q4 = q4 * q4; |
| pvaibhav | 15:4488660e1a3b | 199 | |
| pvaibhav | 15:4488660e1a3b | 200 | // Normalise accelerometer measurement |
| pvaibhav | 15:4488660e1a3b | 201 | norm = sqrt(ax * ax + ay * ay + az * az); |
| pvaibhav | 15:4488660e1a3b | 202 | if (norm == 0.0f) return; // handle NaN |
| pvaibhav | 15:4488660e1a3b | 203 | norm = 1.0f/norm; |
| pvaibhav | 15:4488660e1a3b | 204 | ax *= norm; |
| pvaibhav | 15:4488660e1a3b | 205 | ay *= norm; |
| pvaibhav | 15:4488660e1a3b | 206 | az *= norm; |
| pvaibhav | 15:4488660e1a3b | 207 | |
| pvaibhav | 15:4488660e1a3b | 208 | // Normalise magnetometer measurement |
| pvaibhav | 15:4488660e1a3b | 209 | norm = sqrt(mx * mx + my * my + mz * mz); |
| pvaibhav | 15:4488660e1a3b | 210 | if (norm == 0.0f) return; // handle NaN |
| pvaibhav | 15:4488660e1a3b | 211 | norm = 1.0f/norm; |
| pvaibhav | 15:4488660e1a3b | 212 | mx *= norm; |
| pvaibhav | 15:4488660e1a3b | 213 | my *= norm; |
| pvaibhav | 15:4488660e1a3b | 214 | mz *= norm; |
| pvaibhav | 15:4488660e1a3b | 215 | |
| pvaibhav | 15:4488660e1a3b | 216 | // Reference direction of Earth's magnetic field |
| pvaibhav | 15:4488660e1a3b | 217 | const float _2q1mx = 2.0f * q1 * mx; |
| pvaibhav | 15:4488660e1a3b | 218 | const float _2q1my = 2.0f * q1 * my; |
| pvaibhav | 15:4488660e1a3b | 219 | const float _2q1mz = 2.0f * q1 * mz; |
| pvaibhav | 15:4488660e1a3b | 220 | const float _2q2mx = 2.0f * q2 * mx; |
| pvaibhav | 15:4488660e1a3b | 221 | const float hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4; |
| pvaibhav | 15:4488660e1a3b | 222 | const float hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4; |
| pvaibhav | 15:4488660e1a3b | 223 | const float _2bx = sqrt(hx * hx + hy * hy); |
| pvaibhav | 15:4488660e1a3b | 224 | const float _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4; |
| pvaibhav | 15:4488660e1a3b | 225 | const float _4bx = 2.0f * _2bx; |
| pvaibhav | 15:4488660e1a3b | 226 | const float _4bz = 2.0f * _2bz; |
| pvaibhav | 15:4488660e1a3b | 227 | |
| pvaibhav | 15:4488660e1a3b | 228 | // Gradient decent algorithm corrective step |
| pvaibhav | 15:4488660e1a3b | 229 | s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); |
| pvaibhav | 15:4488660e1a3b | 230 | s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); |
| pvaibhav | 15:4488660e1a3b | 231 | s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); |
| pvaibhav | 15:4488660e1a3b | 232 | s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); |
| pvaibhav | 15:4488660e1a3b | 233 | norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude |
| pvaibhav | 15:4488660e1a3b | 234 | norm = 1.0f/norm; |
| pvaibhav | 15:4488660e1a3b | 235 | s1 *= norm; |
| pvaibhav | 15:4488660e1a3b | 236 | s2 *= norm; |
| pvaibhav | 15:4488660e1a3b | 237 | s3 *= norm; |
| pvaibhav | 15:4488660e1a3b | 238 | s4 *= norm; |
| pvaibhav | 15:4488660e1a3b | 239 | |
| pvaibhav | 15:4488660e1a3b | 240 | // Compute rate of change of quaternion |
| pvaibhav | 15:4488660e1a3b | 241 | const float qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1; |
| pvaibhav | 15:4488660e1a3b | 242 | const float qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2; |
| pvaibhav | 15:4488660e1a3b | 243 | const float qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3; |
| pvaibhav | 15:4488660e1a3b | 244 | const float qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4; |
| pvaibhav | 15:4488660e1a3b | 245 | |
| pvaibhav | 15:4488660e1a3b | 246 | // Integrate to yield quaternion |
| pvaibhav | 15:4488660e1a3b | 247 | q1 += qDot1 * deltat; |
| pvaibhav | 15:4488660e1a3b | 248 | q2 += qDot2 * deltat; |
| pvaibhav | 15:4488660e1a3b | 249 | q3 += qDot3 * deltat; |
| pvaibhav | 15:4488660e1a3b | 250 | q4 += qDot4 * deltat; |
| pvaibhav | 15:4488660e1a3b | 251 | norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion |
| pvaibhav | 15:4488660e1a3b | 252 | norm = 1.0f/norm; |
| pvaibhav | 15:4488660e1a3b | 253 | q.w = q1 * norm; |
| pvaibhav | 15:4488660e1a3b | 254 | q.v.x = q2 * norm; |
| pvaibhav | 15:4488660e1a3b | 255 | q.v.y = q3 * norm; |
| pvaibhav | 15:4488660e1a3b | 256 | q.v.z = q4 * norm; |
| pvaibhav | 15:4488660e1a3b | 257 | } |
| pvaibhav | 43:6251c0169f4f | 258 |