JSantos's profile - activity

Hi,

I'm doing experiments with the frontal sonar ring present in the Pioneer 3DX using ROSARIA with ROS Fuerte. However, the output from the array wasn't what I expected. The sonar readings often return the maximum range of the sonar, even though the wall is clearly not so far away. I made a video where is possible to compare the sonar readings with an LFR in my campus corridors. Also, I have uploaded a photo of the corridor to give a general overview of the scenario.

Video

Campus

Yellow dots are the sonar readings (pointcloud published by ROSARIA), red dots are LFR scans and the green dots can be ignored.

I've tried both ROSARIA and the p2os drivers. Both gave me the same output. I also tried it with two more pioneers available in my lab, but they gave me the same results. Is there an hardware issue with the p3dx sonars? Does anyone know if changing the frequency of the sonar readings solves this issue?

Best regards,

João Santos

Sorry. Link updated.

Hey,

I'm trying to implement occupancy_grid_builder using a Laser Range Finder, firstly in stage and then in a real-world situation. I'm using Ubuntu 11.10 with ROS Fuerte. I already created a launch file :

<node name="mapper" type="mapper" pkg="ethzasl_icp_mapper" output="screen" >
<remap from="scan" to="base_scan" />
<param name="subscribe_scan" value="true"/>
<param name="subscribe_cloud" value="false"/>
<param name="icpConfig" value="$(find ethzasl_icp_mapper)/launch/artor/icp.yaml" />
<param name="inputFiltersConfig" value="$(find ethzasl_icp_mapper)/launch/artor/input_filters.yaml" />
<param name="mapPostFiltersConfig" value="$(find ethzasl_icp_mapper)/launch/artor/map_post_filters.yaml" />
<param name="odom_frame" value="/odom" />
<param name="map_frame" value="/map" />
<param name="useROSLogger" value="true" />
<param name="minOverlap" value="0.8" /> 
<param name="minReadingPointCount" value="1000" /> 
<param name="minMapPointCount" value="10000" /> 
  </node>

<node name="occupancy_grid_builder" pkg="ethzasl_icp_mapper" type="occupancy_grid_builder" output="screen">
  <remap from="scan" to="base_scan" />
</node>

However, I'm getting the following error:

Error

Note: It's possible to see the results from the first iteration on Rviz.

Please, can someone help me out? If anything else is needed, I will gladly post it later.

Thanks in advance :)

I know that isn't the best update rate for this package, but I'm doing slow rotations. I did some experiences and the resulting mapping was exceptional, although this is happening: http://goo.gl/kGWG4 It seems like a V shape laser dead zone and it’s very strange. Also, this happens in stage too.

Thanks! I'm fascinated with your work, it's very interesting. However I have a few questions. I have implemented this package with teleoperation in a robotic platform which has a Hokuyo URG-04LX-UG01 Laser Rangefinder with an update rate of 10Hz.

Hello,

I'm trying to implement a small simulation of hector_mapping package using stage on Ubuntu 11.10 with ROS Fuerte. I changed the launch file within this package in order to be compatible with stage.

Original Launch file:

  <arg name="tf_map_scanmatch_transform_frame_name" default="scanmatcher_frame"/>
  <arg name="base_frame" default="base_footprint"/>
  <arg name="odom_frame" default="nav"/>
  <arg name="pub_map_odom_transform" default="true"/>
  <arg name="scan_subscriber_queue_size" default="5"/>
  <arg name="scan_topic" default="scan"/>
  <arg name="map_size" default="2048"/>

Modified Launch file:

  <arg name="tf_map_scanmatch_transform_frame_name" default="scanmatcher_frame"/>
  <arg name="base_frame" default="base_link"/> <!-- /base_footprint to /base_link -->
  <arg name="odom_frame" default="odom"/> <!-- /nav to /odom -->
  <arg name="pub_map_odom_transform" default="true"/>
  <arg name="scan_subscriber_queue_size" default="5"/>
  <arg name="scan_topic" default="base_scan"/> <!-- /scan to /base_scan -->
  <arg name="map_size" default="2048"/>

However, the results aren't the best. It seems that the robot loses its location and the map is built incorrectly. I would expect the map to be almost perfect, since I am using Stage's built-in odometry. The results can be seen here in this video:

youtube [.dot] com [dash] watch?v=ghQpwf5gYY4 (Sorry I haven't got enough karma to post a video)

In the beginning you can see how I am running the system; and by 3m45s you can see how the map is incorrectly alligned.

Please, can someone help me out? If anything else is needed, I will gladly post it later.

Thanks in advance :)