rtabmap/corelib/src/IMU.cpp

/*
Copyright (c) 2010-2021, Mathieu Labbe - IntRoLab - Universite de Sherbrooke
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the Universite de Sherbrooke nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/


#include <rtabmap/core/IMU.h>

namespace rtabmap {

void IMU::convertToBaseFrame()
{
	if(!localTransform_.isNull() && !localTransform_.rotation().isIdentity())
	{
		cv::Mat rotationMatrix, rotationMatrixT;
		localTransform_.rotationMatrix().convertTo(rotationMatrix, CV_64FC1);
		cv::transpose(rotationMatrix, rotationMatrixT);

		cv::Mat_<double> linearIn = (cv::Mat_<double>(3,1) << linearAcceleration_[0], linearAcceleration_[1], linearAcceleration_[2]);
		cv::Mat_<double> linearOut = rotationMatrix * linearIn;
		linearAcceleration_ = cv::Vec3d(linearOut(0,0), linearOut(1,0), linearOut(2,0));
		if(!linearAccelerationCovariance_.empty())
		{
			linearAccelerationCovariance_ = rotationMatrix * linearAccelerationCovariance_ * rotationMatrixT;
		}

		cv::Mat_<double> angularIn = (cv::Mat_<double>(3,1) << angularVelocity_[0], angularVelocity_[1], angularVelocity_[2]);
		cv::Mat_<double> angularOut = rotationMatrix * angularIn;
		angularVelocity_ = cv::Vec3d(angularOut(0,0), angularOut(1,0), angularOut(2,0));
		if(!angularVelocityCovariance_.empty())
		{
			angularVelocityCovariance_ = rotationMatrix * angularVelocityCovariance_ * rotationMatrixT;
		}

		if(!(orientation_[0] == 0.0 && orientation_[1] == 0.0 && orientation_[2] == 0.0))
		{
			// orientation includes roll and pitch but not yaw in local transform
			Eigen::Quaterniond qTheta =
					Eigen::AngleAxisd(0, Eigen::Vector3d::UnitX()) *
					Eigen::AngleAxisd(0, Eigen::Vector3d::UnitY()) *
					Eigen::AngleAxisd(localTransform_.theta(), Eigen::Vector3d::UnitZ());
			Eigen::Quaterniond q = qTheta * Eigen::Quaterniond(orientation_[3], orientation_[0], orientation_[1], orientation_[2]) * localTransform_.getQuaterniond().inverse();
			orientation_ = cv::Vec4d(q.x(),q.y(),q.z(),q.w());
			if(!orientationCovariance_.empty())
			{
				orientationCovariance_ = rotationMatrix * orientationCovariance_ * rotationMatrixT;
			}
		}

		localTransform_ = Transform(localTransform_.x(), localTransform_.y(), localTransform_.z(), 0,0,0);
	}
}

} //namespace rtabmap