Using RT-SLAM

Configuration

There are no configuration files yet. All the constant variables in capital letters defined at the beginning of the file $JAFAR_DIR/modules/rtslam/demo_suite/demo_slam.cpp are open to tuning. Some important ones are described with more details below.

Camera calibration

You have to modify the following lines in order to setup the camera calibration:

   1 const unsigned IMG_WIDTH = 640;
   2 const unsigned IMG_HEIGHT = 480;
   3 const double INTRINSIC[4] = { 306.2969,   264.7741,   499.9177,   494.4829 };
   4 const double DISTORTION[3] = { -0.2293129, 0.08793152, -0.01349877 };

Running the demo

   1 cd $JAFAR_DIR/build/modules/rtslam
   2 demo_suite/<platform>/demo_slam <options>

Control options:

--disp-2d=0/1 use 2D display
--disp-3d=0/1 use 3D display
--render-all=0/1 (needs --replay 1)
--data-path=/mnt/ram/rtslam
--replay=0/1 (needs --data-path and having dumped here an online demo first)
--dump=0/1 dump the images (--replay=0) or the rendered views (--replay=1) (needs --data-path). If --replay=0, --data-path should be in a ram disk.
--log=0/1 log result in text file
--rand-seed=0/1/n. 0=generate new one, 1=in replay use the saved one, n=use seed n
--pause=0/n. 0=don't, n=pause for frames>n (needs --replay 1)
--verbose=0/1/2/3/4/5. Off/Trace/Warning/Debug/VerboseDebug/VeryVerboseDebug (if compiled in debug only)
--help
--usage

Slam options:

--robot 0=constant vel, 1=inertial
--trigger 0=internal, 1=external with MTI control, 2=external without control
--simu 0/1
--freq camera frequency in double Hz (with trigger==0/1)
--shutter shutter time in double seconds (with trigger==1)

Controlling the demo

When doing a replay, you can control how slam is running by interacting with the 2D viewer:

Press "[space]" to switch between play and pause mode.
Press "N" to process one image when in pause mode.
Press "F" to switch between render-all mode and fast mode.
Press "Q" to quit.
Click on an observation to get textual and visual information about the observation and associated landmark.
Click on an empty part of the image to get information about the sensor and the associated robot.

Interpreting the demo

Color code:

magenta: InitialParametrization landmarks that were observed this frame
dark red: InitialParametrization landmarks that were not observed this frame
cyan: ConvergedParametrization landmarks that were observed this frame
dark blue: ConvergedParametrization landmarks that were not observed this frame

2D landmark representation:

a colored + cross: the predicted position of the landmark
a colored ellipse: the 3-sigma prediction uncertainty
an orange x cross: the measured position of the landmark
a colored label: the id of the landmark, followed by the matching score (/100)

Reasons for a landmark not being observed:

outside of the sensor frame (you can still see them in the 3D view)
matching failed (you can see the matching score that is below the threshold)
the observation was inconsistent (the measure is out of the uncertainty ellipse)
too many landmarks are in the sensor frame and we didn't try to observe some of them (no matching score is present)

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