Albatross's profile - activity

I checked the date on catkin_create_pkg from /usr/local, turns out it was created in 2013, so it must have been from when I was mucking around with ROS in the past. I thought I uninstalled all of the old stuff and replaced it with the new version, but it seems a few things were missed.

Thanks! I've got it working now. Uninstalling with pip or pip3 didn't fix it (got a message saying it couldn't find anything to uninstall) so what I ended up doing was just renaming the file in /usr/local/bin to something else so it wouldn't use that one.

I'm using Ubuntu 14.04 with ROS Indigo. I think installed it with apt-get install python-catkin-pkg, I also did an install of ros-indigo-desktop-full earlier when going through the tutorials, which may have included it?

I'm trying to create a package with catkin_create_pkg but it is failing with this error:

Traceback (most recent call last):
File "/usr/local/bin/catkin_create_pkg", line 10, in <module> from catkin_pkg.package_templates import create_package_files, PackageTemplate ImportError: No module named 'catkin_pkg'

I think this is because it is trying to use Python 3 rather than Python 2. (running python -c "import catkin_pkg" works, but running python3 -c "import catkin_pkg" gives the import error)

Is there a nice way to switch it to always use Python 2 instead (the default Python on my system, and the one I prefer to use)? I just installed it with apt-get following the tutorials. Other stuff like catkin_make and catkin_init_workspace work fine, catkin_create_pkg was the first command I ran into that didn't work.

I'm trying to build ROS fuerte on my debian sid/jessie machine. I'm compiling from source as the apt-get stuff doesn't work for me. Pretty much everything runs fine except packages that depend on the PCL package. When I try to build the gazebo_plugins with rosmake, I get an error like the one below:

  mkdir -p bin
  cd build && cmake -Wdev -DCMAKE_TOOLCHAIN_FILE=`rospack find rosbuild`/rostoolchain.cmake  ..
  [rosbuild] Building package gazebo_plugins
  Failed to invoke /opt/ros/fuerte/bin/rospack deps-manifests gazebo_plugins
  [rospack] Error: package/stack gazebo_plugins depends on non-existent package pcl


  CMake Error at /opt/ros/fuerte/share/ros/core/rosbuild/public.cmake:129 (message):


    Failed to invoke rospack to get compile flags for package 'gazebo_plugins'.
    Look above for errors from rospack itself.  Aborting.  Please fix the
    broken dependency!

  Call Stack (most recent call first):
    /opt/ros/fuerte/share/ros/core/rosbuild/public.cmake:203 (rosbuild_invoke_rospack)
    CMakeLists.txt:4 (rosbuild_init)


  -- Configuring incomplete, errors occurred!

I tried doing rosmake on perception_pcl, but ended up with this error:

  mkdir -p bin
  cd build && cmake -Wdev -DCMAKE_TOOLCHAIN_FILE=`rospack find rosbuild`/rostoolchain.cmake  ..
  [rosbuild] Building package pcl_ros
  [rosbuild] Including /opt/ros/fuerte/share/roscpp/rosbuild/roscpp.cmake
  [rosbuild] Including /opt/ros/fuerte/share/roslisp/rosbuild/roslisp.cmake
  [rosbuild] Including /opt/ros/fuerte/share/rospy/rosbuild/rospy.cmake
  -- [rosbuild] Found SSE3 extensions, using flags: -msse3 -mfpmath=sse
  CMake Error at CMakeLists.txt:21 (find_package):
    By not providing "FindPCL.cmake" in CMAKE_MODULE_PATH this project has
    asked CMake to find a package configuration file provided by "PCL", but
    CMake did not find one.

    Could not find a package configuration file provided by "PCL" with any of
    the following names:

      PCLConfig.cmake
      pcl-config.cmake

    Add the installation prefix of "PCL" to CMAKE_PREFIX_PATH or set "PCL_DIR"
    to a directory containing one of the above files.  If "PCL" provides a
    separate development package or SDK, be sure it has been installed.


  -- Configuring incomplete, errors occurred!

It seems like there is a cmake file missing? I did a grep of my system, and the files it mentions aren't anywhere. I also tried downloading the stand-alone pcl code from github, and these files still don't exist.

I feel like I am doing something wrong, but I am not sure how to fix it, any help would be greatly appreciated. I am new to ROS and fairly new to unix. Let me know if you need any more information. Thanks! :)

I'm trying to create a simple model for a controller of an inverted pendulum.

What I have so far is a model that receives position and velocity from the pendulum, and outputs motor commands. What I want is a physical model that this controller can interact with (using ROS topics to communicate between the two)

I have a feeling this should be relatively simple, but I can't seem to find a good place to start. I think all I need is a rod with mass/intertia with a revolute joint attached to a cart, that can move linearly.

What would you suggest as the best way to set up this environment? I've looked at http://www.openrobots.org/morse/doc/stable/user/actuators/armature.html (armature actuators) in MORSE, but I'm not sure how to build a model that can use them properly.

Any help or suggestions will be much appreciated! :)

I've mostly been using MORSE/Blender, and I'd prefer to keep working with that simulator, but a solution using Gazebo would be okay as well

(I'm using ROS Fuerte on Debian Jessie, with Gazebo 1.7 and MORSE 1.0.1)

EDIT:

Just to follow up in case anyone else runs into a similar problem, here is a list of tutorials that I've found to be helpful:

Accessing and modifying joint state: http://gazebosim.org/wiki/Tutorials/1.3/intermediate/pid_control_joint Revolute joint for the pendulum: http://gazebosim.org/wiki/Tutorials/1.2/control_robot/animate_joint Creating a subscriber for ROS messages: http://gazebosim.org/wiki/Tutorials/1.5/ros_enabled_model_plugin Pendulum control for newer version of Gazebo (doesn't work for me, but might for you): http://gazebosim.org/wiki/Tutorials/1.9/Using_A_URDF_In_Gazebo

Hi All,

I'm trying to read ROS images published from a video camera (from MORSE) into a numpy array in my python script, but I don't know what is the correct way to do this, and everything I have tried hasn't worked.

Does anyone know how to do this?

Here is a snippet of what I have tried so far:

import numpy 
import rospy 
from sensor_msgs.msg import Image

def vis_callback( data ):
  im = numpy.array( data.data, dtype=numpy.uint8 )
  doSomething( im )
rospy.init_node('bla',anonymous=True)
sub_vis = rospy.Subscriber('navbot/camera/image',Image,vis_callback)

rospy.spin()

I get an error that looks like this:

[ERROR] [WallTime: 1370383204.000265] bad callback: <function vis_callback at 0x32e2398>
Traceback (most recent call last):
  File "/opt/ros/fuerte/lib/python2.7/dist-packages/ros_comm-1.8.15-py2.7.egg/rospy/topics.py", line 678, in _invoke_callback
    cb(msg)
  File "ros_simulate.py", line 55, in vis_callback
    im = numpy.array(data.data,dtype=numpy.uint8)
ValueError: invalid literal for long() with base 10: "':\x0f\xff';\x10\xff+A\x12\xff7Q\x16\xffB`\x18\xffGg\x18\xffDa\x15\xff=W\x12\xff2H\r\xff*<\x0b\xff&8\n\xff$6\t\xff%6\t\xff'9\n\xff*>\n\xff0G\x0b\xff8S\x0b\xff;Y\n\xff:X\t\xff8V\x07\xff6T\x06\xff2N\x04\xff-F\x04\xff+B\x03\xff&<\x03\xff(?\x05\xff#8\x07\xff\x1e0\x07\xff\x19)\x07\xff\x19(\x08\xff\x1b+\t\xff\x1e0\x0b\xff\x1e0\x0b\xff 3\x0c\xff\x1e1\x0b\xff\x1e1\x0b\xff\x1d/\n\xff\x1c-\t\xff\x1c,\t\xff\x1a*\x08\xff\x1d.\x08\xff(>\x0b\xff-F\x0c\xff<[\x0f\xffJo\x12\xffJp\x12\xffKr\x12\xffLs\x12\xffMt\x13\xffMu\x13\xff"

I noticed that the Image object has a deserialize_numpy() method, I couldn't find any documentation on how to use it, so I crossed my fingers and tried it out:

def vis_callback( data ):
  im = numpy.array(data.deserialize_numpy(data.data, numpy ), dtype=numpy.uint8)
  doSomething( im )

and got more errors:

[ERROR] [WallTime: 1370383699.289428] bad callback: <function vis_callback at 0x34b5410>
Traceback (most recent call last):
  File "/opt/ros/fuerte/lib/python2.7/dist-packages/ros_comm-1.8.15-py2.7.egg/rospy/topics.py", line 678, in _invoke_callback
    cb(msg)
  File "ros_simulate.py", line 53, in vis_callback
    im = numpy.array(data.deserialize_numpy(data.data, numpy ), dtype=numpy.uint8)
  File "/opt/ros/fuerte/lib/python2.7/dist-packages/sensor_msgs/msg/_Image.py", line 282, in deserialize_numpy
    raise genpy.DeserializationError(e) #most likely buffer underfill
DeserializationError: unpack requires a string argument of length 8

guava version 13+ https://code.google.com/p/guava-libraries/wiki/Release15 DOMSerializer http://mvnrepository.com/artifact/org.apache.ws.commons.util/ws-commons-util/1.0.2 DNS java: sudo apt-get install libdnsjava-java netty: http://mvnrepository.com/artifact/org.jboss.netty/netty/3.2.9.Final

For me I didn't use eclipse, and I had to manually find and download various libraries to get it running. Most things were installed in the /opt/ros/hydro/share/maven/ directory, I kept a list of the other dependencies that I will post below.