mapOptmization.cpp

#include "utility.h"
#include "lio_sam/cloud_info.h"

#include <gtsam/geometry/Rot3.h>
#include <gtsam/geometry/Pose3.h>
#include <gtsam/slam/PriorFactor.h>
#include <gtsam/slam/BetweenFactor.h>
#include <gtsam/navigation/GPSFactor.h>
#include <gtsam/navigation/ImuFactor.h>
#include <gtsam/navigation/CombinedImuFactor.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/nonlinear/LevenbergMarquardtOptimizer.h>
#include <gtsam/nonlinear/Marginals.h>
#include <gtsam/nonlinear/Values.h>
#include <gtsam/inference/Symbol.h>

#include <gtsam/nonlinear/ISAM2.h>

using namespace gtsam;

using symbol_shorthand::X; // Pose3 (x,y,z,r,p,y)
using symbol_shorthand::V; // Vel   (xdot,ydot,zdot)
using symbol_shorthand::B; // Bias  (ax,ay,az,gx,gy,gz)
using symbol_shorthand::G; // GPS pose

/*
    * A point cloud type that has 6D pose info ([x,y,z,roll,pitch,yaw] intensity is time stamp)
    */
struct PointXYZIRPYT
{
    PCL_ADD_POINT4D
    PCL_ADD_INTENSITY;                  // preferred way of adding a XYZ+padding
    float roll;
    float pitch;
    float yaw;
    double time;
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW   // make sure our new allocators are aligned
} EIGEN_ALIGN16;                    // enforce SSE padding for correct memory alignment

POINT_CLOUD_REGISTER_POINT_STRUCT (PointXYZIRPYT,
                                   (float, x, x) (float, y, y)
                                   (float, z, z) (float, intensity, intensity)
                                   (float, roll, roll) (float, pitch, pitch) (float, yaw, yaw)
                                   (double, time, time))

typedef PointXYZIRPYT  PointTypePose;


class mapOptimization : public ParamServer
{

public:

    // gtsam
    NonlinearFactorGraph gtSAMgraph;
    Values initialEstimate;
    Values optimizedEstimate;
    ISAM2 *isam;
    Values isamCurrentEstimate;
    Eigen::MatrixXd poseCovariance;

    ros::Publisher pubLaserCloudSurround;
    ros::Publisher pubLaserOdometryGlobal;
    ros::Publisher pubLaserOdometryIncremental;
    ros::Publisher pubKeyPoses;
    ros::Publisher pubPath;

    ros::Publisher pubHistoryKeyFrames;
    ros::Publisher pubIcpKeyFrames;
    ros::Publisher pubRecentKeyFrames;
    ros::Publisher pubRecentKeyFrame;
    ros::Publisher pubCloudRegisteredRaw;
    ros::Publisher pubLoopConstraintEdge;

    ros::Subscriber subLaserCloudInfo;
    ros::Subscriber subGPS;

    std::deque<nav_msgs::Odometry> gpsQueue;
    lio_sam::cloud_info cloudInfo;

    vector<pcl::PointCloud<PointType>::Ptr> cornerCloudKeyFrames;
    vector<pcl::PointCloud<PointType>::Ptr> surfCloudKeyFrames;
    
    pcl::PointCloud<PointType>::Ptr cloudKeyPoses3D;
    pcl::PointCloud<PointTypePose>::Ptr cloudKeyPoses6D;
    pcl::PointCloud<PointType>::Ptr copy_cloudKeyPoses3D;
    pcl::PointCloud<PointTypePose>::Ptr copy_cloudKeyPoses6D;

    pcl::PointCloud<PointType>::Ptr laserCloudCornerLast; // corner feature set from odoOptimization
    pcl::PointCloud<PointType>::Ptr laserCloudSurfLast; // surf feature set from odoOptimization
    pcl::PointCloud<PointType>::Ptr laserCloudCornerLastDS; // downsampled corner featuer set from odoOptimization
    pcl::PointCloud<PointType>::Ptr laserCloudSurfLastDS; // downsampled surf featuer set from odoOptimization

    pcl::PointCloud<PointType>::Ptr laserCloudOri;
    pcl::PointCloud<PointType>::Ptr coeffSel;

    std::vector<PointType> laserCloudOriCornerVec; // corner point holder for parallel computation
    std::vector<PointType> coeffSelCornerVec;
    std::vector<bool> laserCloudOriCornerFlag;
    std::vector<PointType> laserCloudOriSurfVec; // surf point holder for parallel computation
    std::vector<PointType> coeffSelSurfVec;
    std::vector<bool> laserCloudOriSurfFlag;

    pcl::PointCloud<PointType>::Ptr laserCloudCornerFromMap;
    pcl::PointCloud<PointType>::Ptr laserCloudSurfFromMap;
    pcl::PointCloud<PointType>::Ptr laserCloudCornerFromMapDS;
    pcl::PointCloud<PointType>::Ptr laserCloudSurfFromMapDS;

    pcl::KdTreeFLANN<PointType>::Ptr kdtreeCornerFromMap;
    pcl::KdTreeFLANN<PointType>::Ptr kdtreeSurfFromMap;

    pcl::KdTreeFLANN<PointType>::Ptr kdtreeSurroundingKeyPoses;
    pcl::KdTreeFLANN<PointType>::Ptr kdtreeHistoryKeyPoses;

    pcl::PointCloud<PointType>::Ptr latestKeyFrameCloud;
    pcl::PointCloud<PointType>::Ptr nearHistoryKeyFrameCloud;

    pcl::VoxelGrid<PointType> downSizeFilterCorner;
    pcl::VoxelGrid<PointType> downSizeFilterSurf;
    pcl::VoxelGrid<PointType> downSizeFilterICP;
    pcl::VoxelGrid<PointType> downSizeFilterSurroundingKeyPoses; // for surrounding key poses of scan-to-map optimization
    
    ros::Time timeLaserInfoStamp;
    double timeLaserCloudInfoLast;

    float transformTobeMapped[6];

    std::mutex mtx;

    bool isDegenerate = false;
    Eigen::Matrix<float, 6, 6> matP;

    int laserCloudCornerFromMapDSNum = 0;
    int laserCloudSurfFromMapDSNum = 0;
    int laserCloudCornerLastDSNum = 0;
    int laserCloudSurfLastDSNum = 0;

    bool aLoopIsClosed = false;
    map<int, int> loopIndexContainer; // from new to old
    vector<pair<int, int>> loopIndexQueue;
    vector<gtsam::Pose3> loopPoseQueue;
    vector<gtsam::noiseModel::Diagonal::shared_ptr> loopNoiseQueue;

    nav_msgs::Path globalPath;

    Eigen::Affine3f transPointAssociateToMap;
    Eigen::Affine3f incrementalOdometryAffineFront;
    Eigen::Affine3f incrementalOdometryAffineBack;

    mapOptimization()
    {
        ISAM2Params parameters;
        parameters.relinearizeThreshold = 0.1;
        parameters.relinearizeSkip = 1;
        isam = new ISAM2(parameters);

        pubKeyPoses = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/trajectory", 1);
        pubLaserCloudSurround = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/map_global", 1);
        pubLaserOdometryGlobal = nh.advertise<nav_msgs::Odometry> ("lio_sam/mapping/odometry", 1);
        pubLaserOdometryIncremental = nh.advertise<nav_msgs::Odometry> ("lio_sam/mapping/odometry_incremental", 1);
        pubPath = nh.advertise<nav_msgs::Path>("lio_sam/mapping/path", 1);

        subLaserCloudInfo = nh.subscribe<lio_sam::cloud_info>("lio_sam/feature/cloud_info", 1, &mapOptimization::laserCloudInfoHandler, this, ros::TransportHints().tcpNoDelay());
        subGPS = nh.subscribe<nav_msgs::Odometry> (gpsTopic, 200, &mapOptimization::gpsHandler, this, ros::TransportHints().tcpNoDelay());

        pubHistoryKeyFrames = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/icp_loop_closure_history_cloud", 1);
        pubIcpKeyFrames = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/icp_loop_closure_corrected_cloud", 1);
        pubLoopConstraintEdge = nh.advertise<visualization_msgs::MarkerArray>("/lio_sam/mapping/loop_closure_constraints", 1);

        pubRecentKeyFrames = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/map_local", 1);
        pubRecentKeyFrame = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/cloud_registered", 1);
        pubCloudRegisteredRaw = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/cloud_registered_raw", 1);

        downSizeFilterCorner.setLeafSize(mappingCornerLeafSize, mappingCornerLeafSize, mappingCornerLeafSize);
        downSizeFilterSurf.setLeafSize(mappingSurfLeafSize, mappingSurfLeafSize, mappingSurfLeafSize);
        downSizeFilterICP.setLeafSize(mappingSurfLeafSize, mappingSurfLeafSize, mappingSurfLeafSize);
        downSizeFilterSurroundingKeyPoses.setLeafSize(surroundingKeyframeDensity, surroundingKeyframeDensity, surroundingKeyframeDensity); // for surrounding key poses of scan-to-map optimization

        allocateMemory();
    }

    void allocateMemory()
    {
        cloudKeyPoses3D.reset(new pcl::PointCloud<PointType>());
        cloudKeyPoses6D.reset(new pcl::PointCloud<PointTypePose>());
        copy_cloudKeyPoses3D.reset(new pcl::PointCloud<PointType>());
        copy_cloudKeyPoses6D.reset(new pcl::PointCloud<PointTypePose>());

        kdtreeSurroundingKeyPoses.reset(new pcl::KdTreeFLANN<PointType>());
        kdtreeHistoryKeyPoses.reset(new pcl::KdTreeFLANN<PointType>());

        laserCloudCornerLast.reset(new pcl::PointCloud<PointType>()); // corner feature set from odoOptimization
        laserCloudSurfLast.reset(new pcl::PointCloud<PointType>()); // surf feature set from odoOptimization
        laserCloudCornerLastDS.reset(new pcl::PointCloud<PointType>()); // downsampled corner featuer set from odoOptimization
        laserCloudSurfLastDS.reset(new pcl::PointCloud<PointType>()); // downsampled surf featuer set from odoOptimization

        laserCloudOri.reset(new pcl::PointCloud<PointType>());
        coeffSel.reset(new pcl::PointCloud<PointType>());

        laserCloudOriCornerVec.resize(N_SCAN * Horizon_SCAN);