2018-02-18 14:02:33 +05:30

138 lines
4.3 KiB
C++

////////////////////////////////////////////////////////////////////////////
//
// This file is part of RTIMULib-Teensy
//
// Copyright (c) 2014-2015, richards-tech
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
// Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#include "RTFusion.h"
#include "RTIMUHal.h"
// The slerp power valule controls the influence of the measured state to correct the predicted state
// 0 = measured state ignored (just gyros), 1 = measured state overrides predicted state.
// In between 0 and 1 mixes the two conditions
#define RTQF_SLERP_POWER (RTFLOAT)0.02;
const char *RTFusion::m_fusionNameMap[] = {
"NULL",
"Kalman STATE4",
"RTQF"};
RTFusion::RTFusion()
{
m_debug = false;
m_firstTime = true;
m_enableGyro = true;
m_enableAccel = true;
m_enableCompass = true;
m_gravity.setScalar(0);
m_gravity.setX(0);
m_gravity.setY(0);
m_gravity.setZ(1);
m_slerpPower = RTQF_SLERP_POWER;
}
RTFusion::~RTFusion()
{
}
void RTFusion::calculatePose(const RTVector3& accel, const RTVector3& mag, float magDeclination)
{
RTQuaternion m;
RTQuaternion q;
if (m_enableAccel) {
accel.accelToEuler(m_measuredPose);
} else {
m_measuredPose = m_fusionPose;
m_measuredPose.setZ(0);
}
if (m_enableCompass && m_compassValid) {
q.fromEuler(m_measuredPose);
m.setScalar(0);
m.setX(mag.x());
m.setY(mag.y());
m.setZ(mag.z());
m = q * m * q.conjugate();
m_measuredPose.setZ(-atan2(m.y(), m.x()) - magDeclination);
} else {
m_measuredPose.setZ(m_fusionPose.z());
}
m_measuredQPose.fromEuler(m_measuredPose);
// check for quaternion aliasing. If the quaternion has the wrong sign
// the kalman filter will be very unhappy.
int maxIndex = -1;
RTFLOAT maxVal = -1000;
for (int i = 0; i < 4; i++) {
if (fabs(m_measuredQPose.data(i)) > maxVal) {
maxVal = fabs(m_measuredQPose.data(i));
maxIndex = i;
}
}
// if the biggest component has a different sign in the measured and kalman poses,
// change the sign of the measured pose to match.
if (((m_measuredQPose.data(maxIndex) < 0) && (m_fusionQPose.data(maxIndex) > 0)) ||
((m_measuredQPose.data(maxIndex) > 0) && (m_fusionQPose.data(maxIndex) < 0))) {
m_measuredQPose.setScalar(-m_measuredQPose.scalar());
m_measuredQPose.setX(-m_measuredQPose.x());
m_measuredQPose.setY(-m_measuredQPose.y());
m_measuredQPose.setZ(-m_measuredQPose.z());
m_measuredQPose.toEuler(m_measuredPose);
}
}
RTVector3 RTFusion::getAccelResiduals()
{
RTQuaternion rotatedGravity;
RTQuaternion fusedConjugate;
RTQuaternion qTemp;
RTVector3 residuals;
// do gravity rotation and subtraction
// create the conjugate of the pose
fusedConjugate = m_fusionQPose.conjugate();
// now do the rotation - takes two steps with qTemp as the intermediate variable
qTemp = m_gravity * m_fusionQPose;
rotatedGravity = fusedConjugate * qTemp;
// now adjust the measured accel and change the signs to make sense
residuals.setX(-(m_accel.x() - rotatedGravity.x()));
residuals.setY(-(m_accel.y() - rotatedGravity.y()));
residuals.setZ(-(m_accel.z() - rotatedGravity.z()));
return residuals;
}