Implemented first Hangar-Service
Dependencies: CalibrateMagneto QuaternionMath
Fork of SML2 by
SensorFusion.cpp
- Committer:
- pvaibhav
- Date:
- 2015-04-17
- Revision:
- 25:abb0f208e6a9
- Parent:
- 24:23eae343c631
- Child:
- 26:8f3e4e1a3acc
File content as of revision 25:abb0f208e6a9:
#include "SensorFusion.h" #define DEBUG "SensorFusion" #include "Logger.h" SensorFusion::SensorFusion(I2C &i2c) : delegate(&defaultDelegate), accel(i2c), gyro(i2c), magneto(i2c), q(1, 0, 0, 0), // output quaternion deltat(0.010), // sec beta(0.5) // correction gain { } void SensorFusion::setDelegate(SensorFusion::Delegate &d) { delegate = &d; } bool SensorFusion::start() { accel.powerOn(); accel.start(); magneto.powerOn(); if (magneto.performSelfTest() == false) { return false; } magneto.start(); // Since everything is synced to gyro interrupt, start it last gyro.setDelegate(*this); gyro.powerOn(); gyro.start(); return true; } void SensorFusion::stop() { gyro.stop(); magneto.stop(); accel.stop(); gyro.powerOff(); magneto.powerOff(); accel.powerOff(); } static float const deg_to_radian = 0.0174532925f; static float const radian_to_deg = 57.2957795131f; Vector3 SensorFusion::eulerAngles(Quaternion const &q) const { float const q0 = q.w; float const q1 = q.v.x; float const q2 = q.v.y; float const q3 = q.v.z; float const roll = asin(2*(q0*q2-q3*q1)); float const pitch = atan2(2*(q0*q1+q2*q3), 1 - 2*(q1*q1+q2*q2)); float const yaw = atan2(2*(q0*q3+q1*q2), 1 - 2*(q2*q2+q3*q3)); return Vector3(pitch, roll, yaw); } void SensorFusion::sensorUpdate(Vector3 gyro_degrees) { Vector3 const gyro_reading = gyro_degrees * deg_to_radian; Vector3 const accel_reading = accel.read(); Vector3 const magneto_reading = magneto.read(); updateFilter( accel_reading.x, accel_reading.y, accel_reading.z, gyro_reading.x, gyro_reading.y, gyro_reading.z, magneto_reading.x, magneto_reading.y, magneto_reading.z); Vector3 const fused = eulerAngles(q); delegate->sensorTick(fused, accel_reading, magneto_reading, gyro_degrees, q); } void SensorFusion::updateFilter(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) { float q1 = q.w, q2 = q.v.x, q3 = q.v.y, q4 = q.v.z; // short name local variable for readability float norm; float s1, s2, s3, s4; // Auxiliary variables to avoid repeated arithmetic const float _2q1 = 2.0f * q1; const float _2q2 = 2.0f * q2; const float _2q3 = 2.0f * q3; const float _2q4 = 2.0f * q4; const float _2q1q3 = 2.0f * q1 * q3; const float _2q3q4 = 2.0f * q3 * q4; const float q1q1 = q1 * q1; const float q1q2 = q1 * q2; const float q1q3 = q1 * q3; const float q1q4 = q1 * q4; const float q2q2 = q2 * q2; const float q2q3 = q2 * q3; const float q2q4 = q2 * q4; const float q3q3 = q3 * q3; const float q3q4 = q3 * q4; const float q4q4 = q4 * q4; // Normalise accelerometer measurement norm = sqrt(ax * ax + ay * ay + az * az); if (norm == 0.0f) return; // handle NaN norm = 1.0f/norm; ax *= norm; ay *= norm; az *= norm; // Normalise magnetometer measurement norm = sqrt(mx * mx + my * my + mz * mz); if (norm == 0.0f) return; // handle NaN norm = 1.0f/norm; mx *= norm; my *= norm; mz *= norm; // Reference direction of Earth's magnetic field const float _2q1mx = 2.0f * q1 * mx; const float _2q1my = 2.0f * q1 * my; const float _2q1mz = 2.0f * q1 * mz; const float _2q2mx = 2.0f * q2 * mx; const float hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4; const float hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4; const float _2bx = sqrt(hx * hx + hy * hy); const float _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4; const float _4bx = 2.0f * _2bx; const float _4bz = 2.0f * _2bz; // Gradient decent algorithm corrective step 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); 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); 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); 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); norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude norm = 1.0f/norm; s1 *= norm; s2 *= norm; s3 *= norm; s4 *= norm; // Compute rate of change of quaternion const float qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1; const float qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2; const float qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3; const float qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4; // Integrate to yield quaternion q1 += qDot1 * deltat; q2 += qDot2 * deltat; q3 += qDot3 * deltat; q4 += qDot4 * deltat; norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion norm = 1.0f/norm; q.w = q1 * norm; q.v.x = q2 * norm; q.v.y = q3 * norm; q.v.z = q4 * norm; }