[SLAM学习]ORB_SLAM2中的system的单目Monocular问题汇总

system.h

1 输入图像和时间戳

    // Proccess the given monocular frame
    // Input images: RGB (CV_8UC3) or grayscale (CV_8U). RGB is converted to grayscale.
    // Returns the camera pose (empty if tracking fails).
    cv::Mat TrackMonocular(const cv::Mat &im, const double ×tamp);

 

2 Localization Mode 与reset

    // This stops local mapping thread (map building) and performs only camera tracking.
    void ActivateLocalizationMode();
    // This resumes local mapping thread and performs SLAM again.
    void DeactivateLocalizationMode();

    // Returns true if there have been a big map change (loop closure, global BA)
    // since last call to this function
    bool MapChanged();

    // Reset the system (clear map)
    void Reset();

    // Change mode flags
    std::mutex mMutexMode;
    bool mbActivateLocalizationMode;
    bool mbDeactivateLocalizationMode;

3 Shutdown后执行Save camera trajectory

    // All threads will be requested to finish.
    // It waits until all threads have finished.
    // This function must be called before saving the trajectory.
    void Shutdown();

main.cpp 应用示例

​

    // Stop all threads
    SLAM.Shutdown();

    // Save camera trajectory
    SLAM.SaveKeyFrameTrajectoryTUM("KeyFrameTrajectory.txt");
​

4 GetTrackingState() 状态说明

    // Information from most recent processed frame
    // You can call this right after TrackMonocular (or stereo or RGBD)
    int GetTrackingState();

    // Tracking state
    int mTrackingState;

    // Tracking states
    enum eTrackingState{
        SYSTEM_NOT_READY=-1,
        NO_IMAGES_YET=0,
        NOT_INITIALIZED=1,
        OK=2,
        LOST=3
    };

System.cpp

int System::GetTrackingState()
{
    unique_lock lock(mMutexState);
    return mTrackingState;
}

 

5 三种锁   mMutexReset，mMutexMode，mMutexState

    // Reset flag
    std::mutex mMutexReset;
    bool mbReset;

    // Change mode flags
    std::mutex mMutexMode;
    bool mbActivateLocalizationMode;
    bool mbDeactivateLocalizationMode;

    // Tracking state
    int mTrackingState;
    std::vector mTrackedMapPoints;
    std::vector mTrackedKeyPointsUn;
    std::mutex mMutexState;

 

 

System.cpp

1 程序入口

System::System(const string &strVocFile, const string &strSettingsFile, const eSensor sensor,
               const bool bUseViewer):mSensor(sensor), mpViewer(static_cast(NULL)), mbReset(false),mbActivateLocalizationMode(false),
        mbDeactivateLocalizationMode(false)

2 初始化

    //Initialize the Tracking thread
    //(it will live in the main thread of execution, the one that called this constructor)
    mpTracker = new Tracking(this, mpVocabulary, mpFrameDrawer, mpMapDrawer,
                             mpMap, mpKeyFrameDatabase, strSettingsFile, mSensor);

    //Initialize the Local Mapping thread and launch
    mpLocalMapper = new LocalMapping(mpMap, mSensor==MONOCULAR);
    mptLocalMapping = new thread(&ORB_SLAM2::LocalMapping::Run,mpLocalMapper);

    //Initialize the Loop Closing thread and launch
    mpLoopCloser = new LoopClosing(mpMap, mpKeyFrameDatabase, mpVocabulary, mSensor!=MONOCULAR);
    mptLoopClosing = new thread(&ORB_SLAM2::LoopClosing::Run, mpLoopCloser);

    //Initialize the Viewer thread and launch
    if(bUseViewer)

扩展说明初始化

tracking

Tracking::Tracking(System *pSys, ORBVocabulary* pVoc, FrameDrawer *pFrameDrawer, MapDrawer *pMapDrawer, Map *pMap, KeyFrameDatabase* pKFDB, const string &strSettingPath, const int sensor):
    mState(NO_IMAGES_YET), mSensor(sensor), mbOnlyTracking(false), mbVO(false), mpORBVocabulary(pVoc),
    mpKeyFrameDB(pKFDB), mpInitializer(static_cast(NULL)), mpSystem(pSys), mpViewer(NULL),
    mpFrameDrawer(pFrameDrawer), mpMapDrawer(pMapDrawer), mpMap(pMap), mnLastRelocFrameId(0)

LocalMapping

LocalMapping::LocalMapping(Map *pMap, const float bMonocular):
    mbMonocular(bMonocular), mbResetRequested(false), mbFinishRequested(false), mbFinished(true), mpMap(pMap),
    mbAbortBA(false), mbStopped(false), mbStopRequested(false), mbNotStop(false), mbAcceptKeyFrames(true)

loopClosing

LoopClosing::LoopClosing(Map *pMap, KeyFrameDatabase *pDB, ORBVocabulary *pVoc, const bool bFixScale):
    mbResetRequested(false), mbFinishRequested(false), mbFinished(true), mpMap(pMap),
    mpKeyFrameDB(pDB), mpORBVocabulary(pVoc), mpMatchedKF(NULL), mLastLoopKFid(0), mbRunningGBA(false), mbFinishedGBA(true),
    mbStopGBA(false), mpThreadGBA(NULL), mbFixScale(bFixScale), mnFullBAIdx(0)

3 TrackMonocular转换入口

cv::Mat System::TrackMonocular(const cv::Mat &im, const double ×tamp)
{
    if(mSensor!=MONOCULAR)
    {
        cerr << "ERROR: you called TrackMonocular but input sensor was not set to Monocular." << endl;
        exit(-1);
    }

    // Check mode change
    {
        unique_lock lock(mMutexMode);
        if(mbActivateLocalizationMode)
        {
            mpLocalMapper->RequestStop();

            // Wait until Local Mapping has effectively stopped
            while(!mpLocalMapper->isStopped())
            {
                usleep(1000);
            }

            mpTracker->InformOnlyTracking(true);
            mbActivateLocalizationMode = false;
        }
        if(mbDeactivateLocalizationMode)
        {
            mpTracker->InformOnlyTracking(false);
            mpLocalMapper->Release();
            mbDeactivateLocalizationMode = false;
        }
    }

    // Check reset
    {
        unique_lock lock(mMutexReset);
        if(mbReset)
        {
            mpTracker->Reset();
            mbReset = false;
        }
    }

    cv::Mat Tcw = mpTracker->GrabImageMonocular(im,timestamp);

    unique_lock lock2(mMutexState);
    mTrackingState = mpTracker->mState;
    mTrackedMapPoints = mpTracker->mCurrentFrame.mvpMapPoints;
    mTrackedKeyPointsUn = mpTracker->mCurrentFrame.mvKeysUn;

    return Tcw;
}

cv::Mat Tcw = mpTracker->GrabImageMonocular(im,timestamp);

//Tracking 入口

 

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IMU融合 SetViewerIMUFlag

    // Self defined pointer to save images on my disk:
    void SetSaveImageFlag();
    void SetViewerIMUFlagTrue();
    void SetViewerIMUFlagFalse();