Ana's profile - activity

Done. Thank you very much for the suggestion.

In case somebody else still has the problem, I think I got a workaround: http://answers.ros.org/question/33981... (I am commenting here since I found both threads with the same question, not sure which one to post on)

Hi. I am also working with 2 Turtlebots in Gazebo (ROS Fuerte). I was able to separate both /cmd_vel and /odom topics. Here is what I did:

Go to gazebo_ros_create.h and add a new private variable:

std::string robot_namespace_;

Go to gazebo_ros_create.cpp. Add the following lines in the function GazeboRosCreate::Load (I added it around line 56)

this->robot_namespace_ = "";
if (_sdf->HasElement("robotNamespace")) { 
  this->robot_namespace_ = _sdf->GetElement("robotNamespace")->GetValueString() + "/";
}

With that line you are getting the namespace you assigned for the nodes (in my case turtle_1 and turtle_2). Modify the line corresponding to node_namespace in order to add the robotNamespace String on it:

this->node_namespace_ = "";
if (_sdf->HasElement("node_namespace")) {
  this->node_namespace_ = this->robot_namespace_ + _sdf->GetElement("node_namespace")->GetValueString() + "/";
}

Now go down and find the lines in which you subscribe/advertise the topics /cmd_vel, /odom and /sensor_state and change them to local names cmd_vel, odom and sensor_state. The lines should now look like this:

cmd_vel_sub_ = rosnode_->subscribe("cmd_vel", 1, &GazeboRosCreate::OnCmdVel, this );

sensor_state_pub_ = rosnode_->advertise<turtlebot_node::TurtlebotSensorState>("sensor_state", 1);
odom_pub_ = rosnode_->advertise<nav_msgs::Odometry>("odom", 1);
joint_state_pub_ = rosnode_->advertise<sensor_msgs::JointState>("joint_states", 1);

Finally, rosmake the package (make sure that you generate a new library, erase the ROS_NOBUILD if needed (otherwise the library won't be compiled and your changes won't be effective)

Hope it helps. If you found other way to work around this (other than editing the source code), please let me know.

Thanks!

Ana

Hi,

I am doing a simulation with 2 Turtlebots in Gazebo (using ROS Fuerte). I used different namespaces (turtle1 and turtle2) for each robot in order to get their respective data. However, I noticed that some of the topics (topics with Kinect info) did not change their names. For instance after using this snippet:

<group ns="turtle2">
  <include file="$(find tortuninja)/launch/turtlebotNodes.launch" >
    <arg  name="model_name" value="turtle2" /> 
    <arg name="x" value = "-2.0" />
  </include>
</group>

Topics like /imu/data would become accordingly /turtle2/imu/data. But for others like /camera/depth/points I would still get /camera/depth/points.

I fixed the problem by editing the file ($find turtlebot_description)/urdf/gazebo.urdf.xacro . I changed the global topic names like /camera/depth/points to local ones camera/depth/points. After doing that I was able to get the corresponding namespace in front (and get info from both Kinects).

My question is: Is this the right approach? Or is there any other way to change the namespace for Kinect-topics in Turtlebot other than editing the gazebo.urdf.xacro file?

Thanks!

Ana