lfr's profile - activity

Hello !

I used hector_mapping with a simulated robot. Firstly, I used the default values for all parameters specified on the ROS website http://wiki.ros.org/hector_mapping for hector_mapping. But now, I would like to tune these parameters and I don't understand what the map_multi_res_levels parameter is supposed to do ?

If anyone could help me, I will be grateful.

lfr

Hello,
I want to apply navigation with a Youbot in simulation. I used the simulator provided by ROS and I launch it with the following command:
roslaunch youbot_gazebo_robot youbot.launch

But when I try to move the robot after doing the following indications to bring up the navigation stack: http://wiki.ros.org/youbot_navigation , the robot doesn't move. I have some errors with the hokuyo_node.

I found that the youbot_oodl package provided here: https://github.com/youbot/youbot-ros-... is not functional (the OODL include files are missing).

If someone can help me, I will be grateful,

lfr

Hello !

I try to run the move_base node on a real robot. When I run it in simulation (with another robot), it works successfully.
But, when I try to bring up the navigation stack on a real robot, the move_base action server doesn't come up.
Indeed, when I launch the move_base node, I get continuously the unexpected following warning:

[ WARN] [1466504490.216963462]: Costmap2DROS transform timeout. Current time: 1466504490.2169, global_pose stamp: 1466504032.8989, tolerance: 0.3000

Moreover, when I run my own C++ node in order to send a goal command, the program stays blocked inside the waitForServer loop, this loop is as follows:

while(!ac.waitForServer(ros::Duration(5.0)))
{
    ROS_INFO("Waiting for the move_base action server to come up");
}

I don't understand why it doesn't work and why when I run the move_base node the move_base action server doesn't come up.
If anyone can help me, I would be very grateful,
lfr

update 1

Here the result of the roswtf command:

WARNING: Package "ompl" does not follow the version conventions. It should not contain leading zeros (unless the number is 0).
Loaded plugin tf.tfwtf
No package or stack in context
================================================================================
Static checks summary:

No errors or warnings
================================================================================
Beginning tests of your ROS graph. These may take awhile...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules
running tf checks, this will take a second...
... tf checks complete

Online checks summary:

Found 3 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /teleop:
   * /torso_controller/state

WARNING The following nodes are unexpectedly connected:
 * /mugiro_node->/rqt_gui_py_node_4590 (/tf)

WARNING Received out-of-date/future transforms:
 * receiving transform from [/sickS3000_publisher] that differed from ROS time by -460.430734051s
 * receiving transform from [/Publish_odom_TF] that differed from ROS time by -460.43225327s

You can find the tf tree below:

And the graph here:

Hello !
I want to know how to have a holonomic planner for the navigation of a holonomic or omni-directional robot (KUKA Youbot for example).
The Idea is to be able to move the robot along the y axis without changing its orientation.
I tried to adjust the 'holonomic_robot' value of my planner (dwa planner) to true but the robot continue to not move as I want.

If someone can tell me how to configure my planner in order to do this, I will be very grateful.

lfr

Hello everyone !

I use the eband_local_planner for the navigation of my robot in simulation.
The problem is that when I type the command rosparam list, I can't see the parameters of my planner.
It is the same if I type rosparam get parameter_name, I get a message which says that the requested parameter does not exist.
However, if I load these invisible parameters from a YAML file, I can see their effects but they doesn't appear in the parameter server through the previously indicated commands.
They doesn't appear neither using the rosrun rqt_reconfigure rqt_reconfigure command.
My question is: How to have this visibility ?
I ask that because I want to be able to access these parameters in the parameter server in order to modify the behaviour of my robot from a C++ node.

If anyone can help me, I will be grateful,
lfr

Hi there !

In your launch file, you did not specify what planner to use. Personally, I used the eband_local_planer for omni-directional navigation.
You could try it.
First, add the following lines inside the tag <node pkg="move_base"....> .... </node> :

<param name="base_global_planner" value="navfn/NavfnROS"/>
<param name="base_local_planner" value="eband_local_planner/EBandPlannerROS"/>

Then, you just have to create and fill the YAML file for the configuration of the eband_local_planner, let's call it eb_planner.yaml for example.
You have to load this file inside the same tags as previously mentioned (move_base) as follows:

<rosparam file="$(find your_package_name)/config/eb_planner.yaml" command="load" />

(I supposed you put your yaml file inside a folder named "config", of course, you can put it where you want).

You can find all the information about the eband_local_planner here: eband_local_planner

I sincerely hope it will help you,
lfr

Hello, I'm not sure if it is what you want but you can use the SLAM for localization.
You can use hector_mapping (hector_slam), I know it is possible to use it without odometry.
There is also another algorithm for SLAM: slam_gmappping (gmapping) but I don't know if it is possible to use it without odometry.
You can find all the information about those 2 methods on the ros wiki (by typing hector_slam and gmapping).

I hope it will help you,
lfr

I don't know if it will work but you can try to write <ros/ros.h> instead of "ros/ros.h"

Hello,

I don't know if I understood your question correctly but perhaps you should use the navigation stack with move_base. You will be able to move the robot to a desired position.
These links can help you: navigation stack - move_base

I hope it will help you,
lfr

You're welcome

Yes, you can do autonomous driving, of course. I just said that you cannot expect to have real-time reactions using ROS. With real-time, I thought very fast computations (needed in case of outdoor autonomous driving).

The problem is not move_base but ROS. It is unable to respect fast real-time constraints. If you want fast responses, I think using ROS is not the best idea. Obviously it depends on the complexity of the computations (ROS is able to compute simple algorithms in real-time).

It worked successfully, /move_base/TrajectoryPlannerROS/controller_frequency had been set to 15.0. If you want to modify /move_base/controller_frequency, then add controller_frequency: 15.0 before the TrajectoryPlannerROS: line in your yaml file (and with the same indentation).

I think it should work. In your move_base.launch, you have to have the following lines somewhere:

...
<node pkg="move_base" type="move_base" respawn="false" name="move_base" output="screen">
   ...
   <rosparam file="$(find your_package)/config/base_local_planner_params.yaml" command="load"/>
   ...
</node>
...

I write ... to notify the rest of your launch file which is not important concerning your problem.
Of course, you have to fill your yaml file as follows:

...
TrajectoryPlannerROS:
   ...
    controller_frequency: 15.0
   ...

And now, it should work properly. You can check the existence of the parameter using the command rosparam list | grep controller_frequency and you can check its value using the command rosparam get "the output of the previous command" which is supposed to return 15.0.

I hope it will help you,
lfr

As Dirk Thomas well said, the problem is that your user name contains a '@'. When you create a package, catkin_create_package get your user name and put it inside your package.xml as follows:

username@todo.todo

And, it seems that if the email address is not valid, the process will stop.
The only solution I can see now is to change your user name and choosing a "good one".

I hope it helps you,
lfr

Hello !

I need to migrate some packages from ros groovy to ros indigo.
My problem is that one of these packages have a dependency with gazebo_worlds. For Indigo, I saw that this is gazebo_ros_pkgs which replaced gazebo_worlds.
My question is: why is the gazebo_ros_pkgs empty ? It contains only a package.xml and therefore, when I run catkin_make, I get the following error:

CMake Error at /opt/ros/indigo/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
  Could not find a package configuration file provided by "gazebo_ros_pkgs"
  with any of the following names:

    gazebo_ros_pkgsConfig.cmake
    gazebo_ros_pkgs-config.cmake

Moreover, some of launch files of the concerned package use stuffs inside the gazebo_worlds package.

If someone could help me, I will be very grateful,
lfr

Hello,

I give this answer because it is possible that someone else have the same problem.

I found that the problem is with the communication between the robot and my computer.
Indeed, some packets are loss (I saw that in trying to ping the robot). And each time I lose a packet, this is exactly when the second warning appear.
Moreover, sometimes, the delay in communication exceeds my transform_tolerance (I saw that with the ping too) and this is when the first warning appear.

The only solution I can see is to improve the communication way.

I hope it can help someone to find the problem,
lfr

Thanks for answering me. The launch files are correct. I found the problem is the communication between the robot and my computer. There are some packets which are loss.

Hello !

I try to run the navigation stack with a real robot (move_base + gmapping).
My problem is that when I launch my launch file which is supposed to run the move_base node and the slam_gmapping node (and load my YAML configuration files), I get completely randomly warnings which disturb the behaviour of my robot.

When I send no goal, I get this warning randomly:

Costmap2DROS transform timeout ... could not get robot pose, cancelling pose reconfiguration

And when I send a goal, I get this warning randomly:

Unable to get starting pose of robot, unable to create global plan

When the first warning appear, the robot begins to get an hesitating behaviour with very slow speeds.
I didn't find anywhere a real solution to this problem.
If anyone could help me, I would be very grateful,
lfr

Good luck !

You have to write the includes you need (ros.h, ...) and you will be able to use the ros functions as you want. You can write data on topics in order to interact with other nodes (or use the ros services). If you want to set parameters, you would be able to interact with the ros parameter server.