Best parameters for warehouse SLAM using ZED M

[stevemartinov]

Hi Mathieu,

I have purchased ZED M recently and I remember you gave me this link:
http://official-rtab-map-forum.206.s1.nabble.com/Few-questions-regarding-stereo-mapping-with-RTAB-ROS-td5589.html

So I have decided to test the SLAM with ZED M using the parameters you have suggested on that post. Before doing the SLAM, I wanted to ask some questions:

1. Would you recommend to use ZED M depth estimation and send rgbd_d to rtabmap or just send stereo images and let rtabmap do the depth estimation?

2. I have used these parameters and can you say whether I made a good choice? I have read the parameters one by one but thought you might suggest something (I am using the camera for SLAM and also wheel odometry):

           

<param name="RGBD/OptimizeMaxError" type="double" value="0.1"  />
            <param name="RGBD/NeighborLinkRefining" type="string" value="true"/>
            <param name="RGBD/ProximityBySpace"     type="string" value="false"/>
            <param name="RGBD/OptimizeFromGraphEnd" type="string" value="false"/>
            <param name="RGBD/AngularUpdate"        type="string" value="0.05"/>
            <param name="RGBD/LinearUpdate"         type="string" value="0.05"/>
            <param name="Optimizer/Slam2D"          type="string" value="true"/>
            <param name="Vis/MinInliers"            type="string" value="20"/>
            <param name="Vis/InlierDistance"        type="string" value="0.1"/>
            <param name="Kp/MaxDepth"               type="string" value="1.75"/>
            <param name="Vis/MaxDepth"              type="string" value="1.75"/>
            <param name="Rtabmap/TimeThr"           type="string" value="700"/>
            <param name="Rtabmap/DetectionRate"     type="string" value="$(arg rate)" />
            <param name="Mem/RehearsalSimilarity"   type="string" value="0.45"/>
            <param name="Grid/MaxObstacleHeight"    type="string" value="1.7" />
            <param name="Grid/NoiseFilteringRadius" type="string" value="0.05"/>
            <param name="Grid/NoiseFilteringMinNeighbors" type="string" value="5"/>
            <param name="Grid/3D" type="bool" value="false"/>
            <param name="Grid/RayTracing" type="bool" value="true"/>

[matlabbe]

Hi,

1. It depends. If you look for accurate 3D map indoor, you may use stereo mode as rtabmap will do depth estimation only where there is a lot of texture (on edges). Using ZED-M depth can be useful to not have to estimate it on CPU as it would be computed on GPU.

2. For RGBD/OptimizeMaxError, it should be >1, default is 3. The "0.1" may be referring to old way that parameter was used. Now it is a relative ratio against link's covariance instead of absolute distance. "Vis/InlierDistance" is ignored here, as "Vis/EstimationType=1" by default. "Kp/MaxDepth" and "Vis/MaxDepth" are quite small, default is 0 (infinity). Set "Rtabmap/TimeThr" to 0 if you don't want memory management behavior (maybe easier to debug SLAM before going into the memory management problem).

cheers,
Mathieu