rostopic echo /ground_plane returning [nan, nan, nan] for ground plane estimation launch file

[marcuskohtongjie95]

Hi all, I am running the upper_body_detector and ground_plane_estimated in simulation only (gazebo/rviz) and have installed the real_sense_gazebo_plugin (r200 camera).
I remapped the topics of ground_plane_estimation.launch to subscribe the the r200 camera as follow:

<arg name="camera_namespace" default="/r200/camera" /> <arg name="depth_image" default="/depth/image_raw" /> <arg name="camera_info_rgb" default="/color/camera_info" /> <arg name="ground_plane" default="/ground_plane" />

However when i run the ground_plane_estimated.launch and i rostopic echo /ground_plane I get the following msgs

header:
seq: 180
stamp:
secs: 4107
nsecs: 219000000
frame_id: "color"
n: [nan, nan, nan]
d: inf

header:
seq: 181
stamp:
secs: 4107
nsecs: 888000000
frame_id: "color"
n: [nan, nan, nan]
d: nan

Running the upper_body_detector image works fine, meaning that i am able to visualise the topic /upper_body_detector/image but however i am unable to get a detection (either by the bounding box in rqt_image or marker array in rviz), thus i think that the lack of detection is due to the /ground_plane topic not publishing correctly.
I initially thought the problem was because in gazebo, the depth camera is unable to capture the invisible(?) ground plane so i placed a flooring (actually a piece of wall laid flat on the floor) below the robot but that doesnt seem to solve the issue.
Can anyone help me out with this i would be very grateful thanks!

[FooKii]

hey, im also using gazebo. By running people_tracker_standalone.launch i can successully have human identified by upper-body-detection (marker seen in rviz). maybe it can help u somehow.
I do have problem when running people_tracker_robot.launch where i can have result from leg_detector but nothing from upper-body-detector.

[marcuskohtongjie95]

hi thanks for the reply, i couldn't solve this issue so I changed to the darket_yolo package for human detection instead and its working great for me

[FooKii]

hi, it's me again cause i ran into the same problem.
I guess the reason is that your camera's angle or height make it impossible to see the "ground".
The solution is to switch to fixed_groundplane, but i'm guessing u then have the problem caused by "PTU" (e.x. i dont have a ptu integrated), this then involve the issue #177 which is still open.

I fixed by modifying fixed_gp.cpp (modified ugly but it works).

If you still need this, let me know, i try to make a pull request.

OR: if your robot is static or u just want it to work, a quick fix will be set /ptu_state to /joint_states in ground_plane_fixed.launch

[marcuskohtongjie95]

Hi there!
My camera (RealSense r200) is placed 1 meter above the ground and sees the ground just fine. I also do not have a PTU integrated as well and my robot is moving so i don't think I can apply the quick fix that you mentioned.