Arn-O's profile - activity

Hi.

I would like to handle animation sequences for a robot. Is there a way to manage this using a ROS package?

Here are the features that I would expect from such a package:

• manage a sequence "data container" for sequences manipulation
• read this container to activate the robot joints
• view/edit this container
• generate containers from recordings
• generate containers with tools similar to a 3D graphics animation software (like Blender or Maya), using keyframes or IK

I have found this one, which looks in line with my requirement, but unfortunately for the PR2 only: http://wiki.ros.org/puppet

Bags could be also a part of the solution (data container management): http://wiki.ros.org/rosbag

Any feedback appreciated, could it be a similar requirement, documentations, contact, etc.

Yes, I have removed everything some time at the beginning of the year

Correct, it is not that "dynamic". My assumption is that you cannot make it dynamic, since it is designed for robot description, and robot description are supposed to be "static". Not nice for coders, but XML is not really a programming language, just a markup language.

Well, this question is a bit old, but you can look at this repo:

https://github.com/Arn-O/youbot_ros_t...

Hi.

I see a bunch of robots model in Gazebo and I wonder if it is possible to control them. I read the tutorial explaining how to adapt a robot model to do that. Since there are many models in Gazebo, they could be delivered with everything required to manipulate them.

I did not find any clue to do that.

Thanks for the help.

Duplicate with: http://answers.gazebosim.org/question/6654/gazeboos-x-109-no-valid-hardware-interface-element/

I have posted an issue in the ros_control bug tracker: https://github.com/ros-controls/ros_control/issues/177

Finally posted an issue in GitHub: https://github.com/ros/ros_comm/issues/421

I have found the same issue on the Gazebo forum: http://answers.gazebosim.org/question/6271/getting-remote-endpoint-failed-let-gazebo-gui/

Any ideas are welcome. Do you think that it could come from my hardware? (LENOVO T400)

Hi.

I am working on ROS Indigo on Ubuntu 14.04 LTE Thrusty (OK, I know it is not yet released).

When I try to start Gazebo, it fails most of the time (1 time in 10, it works). I use the simple command:

$ roslaunch gazebo_ros empty_world.launch

Here are the messages:

$ roslaunch gazebo_ros empty_world.launch
... logging to /home/arnaud/.ros/log/251a3d96-e35b-11e3-9539-0016eae586be/roslaunch-hercules-11967.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://hercules:46195/

SUMMARY
========

PARAMETERS
 * /rosdistro: <...>
 * /rosversion: <...>
 * /use_sim_time: True

NODES
  /
    gazebo (gazebo_ros/gzserver)
    gazebo_gui (gazebo_ros/gzclient)

auto-starting new master
process[master]: started with pid [11979]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to 251a3d96-e35b-11e3-9539-0016eae586be
process[rosout-1]: started with pid [11992]
started core service [/rosout]
process[gazebo-2]: started with pid [12016]
/opt/ros/indigo/lib/gazebo_ros/gzserver: 5: [: Linux: unexpected operator
process[gazebo_gui-3]: started with pid [12020]
/opt/ros/indigo/lib/gazebo_ros/gzclient: 5: [: Linux: unexpected operator
Gazebo multi-robot simulator, version 2.2.2
Copyright (C) 2012-2014 Open Source Robotics Foundation.
Released under the Apache 2 License.
http://gazebosim.org

Gazebo multi-robot simulator, version 2.2.2
Copyright (C) 2012-2014 Open Source Robotics Foundation.
Released under the Apache 2 License.
http://gazebosim.org

Msg Waiting for masterError [Connection.cc:787] Getting remote endpoint failed
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >'
  what():  remote_endpoint: Transport endpoint is not connected
[ INFO] [1400946636.551182005]: Finished loading Gazebo ROS API Plugin.
Msg Waiting for master
[ INFO] [1400946636.557603492]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
Msg Connected to gazebo master @ http://127.0.0.1:11345
Msg Publicized address: 192.168.1.211
Aborted (core dumped)
[gazebo_gui-3] process has died [pid 12020, exit code 134, cmd /opt/ros/indigo/lib/gazebo_ros/gzclient __name:=gazebo_gui __log:=/home/arnaud/.ros/log/251a3d96-e35b-11e3-9539-0016eae586be/gazebo_gui-3.log].
log file: /home/arnaud/.ros/log/251a3d96-e35b-11e3-9539-0016eae586be/gazebo_gui-3*.log
[ INFO] [1400946637.091142150, 0.022000000]: waitForService: Service [/gazebo/set_physics_properties] is now available.
[ INFO] [1400946637.167613885, 0.093000000]: Physics dynamic reconfigure ready.
^C[gazebo-2] killing on exit
[rosout-1] killing on exit
[master] killing on exit
shutting down processing monitor...
... shutting down processing monitor complete
done

This one fails either:

roscore & rosrun gazebo_ros gazebo

The only way I found to make it work is to start one by one, roscore, gzserver and gzclient.

Does it come from the unstable state of ROS Indigo? Any idea how to fix this?

Thanks.

Hi.

I cannot use rqt_gui since the last update. The topic drill down is updating without any results:

And when I click on refresh, I have this message:

Traceback (most recent call last):
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_publisher/publisher_widget.py", line 103, in _update_thread_run
    for base_type_str in rosmsg.list_msgs(package, rospack=rospack):
NameError: global name 'rospack' is not defined

I have just re-installed everything this weekend so my settings are clean (I already had this message before the update).

Thx for the support.

PS: rospack is installed.

EDIT1: as requested in the comments.

arnaud@hercules:~$ dpkg -p ros-hydro-rqt-publisher
Package: ros-hydro-rqt-publisher
Priority: extra
Section: misc
Installed-Size: 145
Maintainer: Dorian Scholz <<a href="mailto:scholz@sim.tu-darmstadt.de">scholz@sim.tu-darmstadt.de</a>>
Architecture: amd64
Version: 0.3.1-0raring-20131010-0322-+0000
Depends: python-rospkg, ros-hydro-qt-gui-py-common, ros-hydro-roslib, ros-hydro-rosmsg (>= 1.9.49), ros-hydro-rqt-gui, ros-hydro-rqt-gui-py, ros-hydro-rqt-py-common
Size: 21496
Description: rqt_publisher provides a GUI plugin for publishing arbitrary messages with fixed or computed field values.
Homepage: <a href="http://ros.org/wiki/rqt_publisher">http://ros.org/wiki/rqt_publisher</a>

Hi.

I'm working on a robotic arm and I have this code block 5 times in my urdf file:

  <!-- arm_1 link -->
<link name="arm_1_link">
  <inertial>
    <mass value="${arm_1_link_mass}" />
    <inertia ixx="0.010" ixy="0.000" ixz="0.000" iyy="0.010" iyz="0.000" izz="0.010" />
  </inertial>

  <visual>
    <geometry> 
      <mesh filename="package://youbot_description/meshes/arm_joint_1.dae"/>
    </geometry> 
  </visual>
</link>

  <!-- arm_1 joint -->
    <joint name="arm_1_joint" type="revolute">
      <origin xyz="${arm_1_link_pose_x} ${arm_1_link_pose_y} ${arm_1_link_pose_z}" 
              rpy="${arm_1_link_orient_r} ${arm_1_link_orient_p} ${arm_1_link_orient_y}" />
      <parent link="arm_base_link"/>
      <child link="arm_1_link" />
      <axis xyz="${arm_1_axis}" />
      <limit lower="${arm_1_limit_min}" upper="${arm_1_limit_max}"
             effort="${arm_joint_effort}" velocity="${arm_joint_velocity}" />
    </joint>

I would like to use a smart macro to only have one block called 5 times. I would ideally only use the joint number as a parameter. The values are stored on another file in xacro:property.

The issue: how to transform this ${arm_1_limit_min} with a parameter? ${arm_${param_name}_limit_min} does not work.

Thanks for your answers!

Hi.

Is there an easy way or a package to compute forward kinematics from an URDF file? The idea behind is to "explore" the workspace of a robot, plotting reachable points and dexterous area.

As far as I understand the document, TF is for tracking frames. KDL could do the tricks, but did not see if it is possible to use the URDF description of the robot to feed it.

Thanks in advance.

Hello.

It looks like the joint rotation is given with the roll, pitch and yaw in this order:

http://wiki.ros.org/urdf/XML/joint

And too bad, the document of the robot I'm working on is in the ypr order. And moreover, this last oder looks more common, as I found a lot of documentation based on this convention.

How to convert ypr to rpy?

Why has it been changed for ROS? Am I the only one to be disturbed by this?

Thanks in advance for the support.

Hello.

I have just found that my rviz is broken. With several messages no transform from [child_frame] to [parent_frame]. Sorry, I cannot post screenshots.

Any idea to fix this?

Ar.

Note: I have done the test with rrbot, the gazebo test package and my own robot model.

Hello.

I'm working on a teleop program in Python. I want to change a joint position and add an offset read from the keyboard.

So I need to read a topic value to add the offset and send the command with the target value. Of course I have read the tutorial about the subscriber in Python. My requirement is slightly different. I do not want to process a piece of code each time a value is published. I do not even need a fresh value, since I consider that the last published one is sufficient.

So is there a way to get this last published value using rospy?

Thanks for your help.