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pointcloud_to_laserscan rotation of scan line

asked 2015-03-21 13:10:41 -0500

rnunziata gravatar image

updated 2015-03-23 17:57:03 -0500

I am running pointcloud_to_laserscan . When I display the pointcloud2 in rviz after rotation the camera frame is displays correctly along the rviz ground plane. However the laser from pointcloud_to_laserscan produces a scan line that does not register to the cloud2 in rviz .

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from rostopic list

/camera_info
/clicked_point
/clock
/cmd_vel
/depth/image_raw
/depth/points
/gazebo/link_states
/gazebo/model_states
/gazebo/parameter_descriptions
/gazebo/parameter_updates
/gazebo/set_link_state
/gazebo/set_model_state
/gmapping_node/entropy
/image_raw
/image_raw/compressed
/image_raw/compressed/parameter_descriptions
/image_raw/compressed/parameter_updates
/image_raw/compressedDepth
/image_raw/compressedDepth/parameter_descriptions
/image_raw/compressedDepth/parameter_updates
/image_raw/theora
/image_raw/theora/parameter_descriptions
/image_raw/theora/parameter_updates


 self.msgAry  = [self.createStaticTransform("base_footprint",  0,  0,  0.1,  "base_link", 0, 0, 0),   \
                 self.createStaticTransform("base_link",  -0.13,  -0.13,  0.1,  "left_wheel", 0, 0, 0),   \
                 self.createStaticTransform("base_link",  -0.13,  0.13,  0.1,  "right_wheel", 0, 0, 0),   \
                 self.createStaticTransform("base_link",  -0.1,  0,  0.1,  "tower_link", 0, 0, 0),   \
                 self.createStaticTransform("tower_link", 0.0,  0,  0.2,  "camera_link", 0, 0, 0),  \
                 self.createStaticTransform("camera_link", 0,  0,  0,  "camera_frame_optical", 0, 0, 0),  \
                 self.createStaticTransform("camera_link", 0, 0,  0,  "rrbot/camera_frame",  -1.57079633,  0,  -1.57079633)]  

 self.pub_tf.publish(self.msgAry)




  <!-- ******************************************************************************************** -->

  <node name="pointcloud_to_laserscan_node" pkg="pointcloud_to_laserscan" type="pointcloud_to_laserscan_node"  output="screen" respawn="true">
      <remap from="cloud_in" to="/depth/points"/>
      <rosparam>
            target_frame: "camera_frame_optical"
            tolerance: 0.01
            min_height: 1.0
            max_height: 10.0

            angle_min: -1.5708 # -M_PI/2
            angle_max: 1.5708 # M_PI/2
            angle_increment: 0.00436717644334
            scan_time: 0.3333
            range_min: 0.1
            range_max: 30.0
            use_inf: false

            # Concurrency level, affects number of pointclouds queued for processing and number of threads used
            # 0 : Detect number of cores
            # 1 : Single threaded
            # 2->inf : Parallelism level
            concurrency_level: 0
       </rosparam>
  </node>

eg: of scan output

header: 
  seq: 530
  stamp: 
    secs: 435
    nsecs: 155000000
  frame_id: rrbot/camera_frame
angle_min: -1.57079994678
angle_max: 1.57079994678
angle_increment: 0.00436717644334
time_increment: 0.0
scan_time: 0.333299994469
range_min: 0.10000000149
range_max: 30.0
ranges: [31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31.0, 31 ...
(more)
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2 Answers

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answered 2015-03-21 18:59:25 -0500

paulbovbel gravatar image

This is probably due to you not providing pointcloud_to_laserscan with a target frame. Camera frames are differently oriented ( http://www.ros.org/reps/rep-0103.html... ). Pointcloud_to_laserscan projects the pointcloud onto the x-y plane, so if the camera frame is used, the laserscan will end up 'vertical'.

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Comments

The point cloud comes from the depth points from the gazebo kentic plugin which is converted to a scan line with a target frame of rrbot/camera_frame which is the same frame the riviz point cloud2 is using to display the voxel image. You can see both in the images.

rnunziata gravatar image rnunziata  ( 2015-03-22 11:28:12 -0500 )edit

Yes, and the camera_frame is oriented differently than you may expect (z-forward, x-right, y-up). pointcloud_to_laserscan will try to output a laserscan on the x-y plane, which is why it's 'upright'. Use a body-oriented frame (x-forward, y-left, z-up) such as 'base_link' as the target frame.

paulbovbel gravatar image paulbovbel  ( 2015-03-22 11:39:04 -0500 )edit

OK...tried to reset the target frame in PtoS and get this error which I do not understand

Can't transform pointcloud from frame rrbot/camera_frame to camera_frame_optical  with tolerance 0.01
rnunziata gravatar image rnunziata  ( 2015-03-22 15:18:35 -0500 )edit

https://github.com/ros-perception/per...

This means there's a problem with your transform tree. Post the results of rqt_graph.

paulbovbel gravatar image paulbovbel  ( 2015-03-22 15:25:03 -0500 )edit

If you have a camera_frame and camera_frame_optical, then camera_frame should hypothetically be fine to use as a target_frame. You want to avoid using frames that use the _optical convention.

paulbovbel gravatar image paulbovbel  ( 2015-03-22 15:26:05 -0500 )edit

I have updated the problem statement to include additional data.

rnunziata gravatar image rnunziata  ( 2015-03-22 16:12:42 -0500 )edit

Looks like you have a weird prefixing thing going on. Your pointclouds are coming in with frame "rrbot/camera_frame", but your tf tree contains "rrbot_camera_frame"

paulbovbel gravatar image paulbovbel  ( 2015-03-22 16:56:32 -0500 )edit

I saw that but assumed it was how it handled the display was not an issue. I does find the frame and processes it with rotation on the static transform which is displayed correctly in rviz.

rnunziata gravatar image rnunziata  ( 2015-03-22 17:27:57 -0500 )edit
0

answered 2015-06-08 03:22:49 -0500

Kushaagra gravatar image

I am also getting a similar problem with the following message. Can't transform pointcloud from frame camera_depth_frame_optical to camera_depth_frame with tolerance 0.01. Could someone guide how to solve this issue.

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Asked: 2015-03-21 13:10:41 -0500

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Last updated: Mar 23 '15