yclin's profile - activity

Hello Everyone:

I came across such error when I tried to gazebo from a launch file today:

/opt/ros/fuerte/stacks/simulator_gazebo/gazebo/scripts/gui: line 2: 6038 Segmentation fault (core dumped) rospack find gazebo/gazebo/bin/gzclient -g rospack find gazebo/lib/libgazebo_ros_paths_plugin.so

[gazebo_gui-3] process has died [pid 6035, exit code 139, cmd /opt/ros/fuerte/stacks/simulator_gazebo/gazebo/scripts/gui __name:=gazebo_gui __log:=/home/yucong/.ros/log/741af39e-2cb9-11e3-b8e5-002564043504/gazebo_gui-3.log]. log file: /home/yucong/.ros/log/741af39e-2cb9-11e3-b8e5-002564043504/gazebo_gui-3*.log

the launch file is: <launch>

<arg name="paused" default="false"/> <arg name="use_sim_time" default="true"/> <arg name="gui" default="true"/> <arg name="throttled" default="false"/>

<group if="$(arg use_sim_time)"> </group>

<node name="gazebo" pkg="gazebo" type="gazebo" args="-u $(find gazebo_worlds)/worlds/empty.world" respawn="false" output="screen"/>

<group if="$(arg gui)"> <node name="gazebo_gui" pkg="gazebo" type="gui" respawn="false" output="screen"/> </group>

</launch> but I didn't see anything wrong with the launch file. The error occurs repeatedly but not continuously. Sometimes, it worked ok.

Can someone help me? THank you in advance.

Thanks Johannes, it resolve my doubts

Hi Everyone: In the link http://wiki.ros.org/hector_quadrotor_controller?distro=fuerte, it says Simple Quadrotor Controller plugin implements the controller of the quadrotor. But I do not understand how it runs as a plugin. It seems that it is not compiled and linked into a node, but Gazebo automatically starts it because quadrotor_simple_controller.urdf.xacro was included somewhere in a launch file. I wonder if some one can give me an idea of how it runs? Thank you in advance

Kind Regards Yucong

Hi Everyone: Did anyone of you try to record a gazebo simulation into a video? The only instructions available is https://alliance.seas.upenn.edu/~meam620/wiki/index.php?n=Roslab.RecordingSimulations

following it, I installed glc-capture but still I have no idea of how to record a simulation. the format of the command should be: ./glc-capture [capture option]... [application] [application argument]... but for gazebo, I don't know how to fill in the [application]

Any help is appreciated.

Yucong

Hi Everyone: I tried to load a static image in ROS: here is the part of code: #include <highgui.h> #include <cv.h> using namespace std; using namespace cv;

       int main (int argc, char** argv) {
       ...........................
       if( ! cvLoadImage("13_45_07-65.bmp") ) cout << "sorry" << endl;
      ............................
       }

 in the log file, I can find a " sorry ", which means the image is not successfully loaded.

 the code works well outside ros. I put it in ROS because I need the images to tell when to send geometry_msg.

 I use ROS electric and configure OpenCV-2.3.1 according to http://www.ros.org/wiki/opencv2.  
 OpenCV is used with ROS as a rosdep system dependency      

 I put the followings in the CMakeLists.txt of the package the code is in.
 "  find_package(OpenCV REQUIRED)

if(OpenCV_FOUND) message("====== Found ${OpenCV_VERSION} =======") message("=== ${OpenCV_LIBS}======") endif(OpenCV_FOUND) "

the cmake .. returns: ====== Found 2.3.1 ======= === opencv_gpu;opencv_contrib;opencv_legacy;opencv_objdetect;opencv_calib3d;opencv_features2d;opencv_video;opencv_highgui;opencv_ml;opencv_imgproc;opencv_flann;opencv_core======

I have no idea why this simple OpenCV command in my code cannot be executed in ROS. Anyone can help me? Thank you in advance.

Yucong