roy's profile - activity

Guys,

I am trying to install the Fetch model on my machine but failed to do so due to following error:

roy@RoysMacUbuntu:~/ws/src/stockroom_bot$ sudo apt-get install ros-indigo-fetch*
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package ros-indigo-fetch*
E: Couldn't find any package by glob 'ros-indigo-fetch*'

I also tried ros-kinetic-fetch* (because I am using ROS kinetic). Didn't work either:

roy@RoysMacUbuntu:~/ws/src/stockroom_bot$ sudo apt-get install ros-kinetic-fetch*
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package ros-kinetic-fetch*
E: Couldn't find any package by glob 'ros-kinetic-fetch*'
E: Couldn't find any package by regex 'ros-kinetic-fetch*'

I ran apt-get update already.

Any idea where the problem might be?

Many thanks for your time.

Hi folks,

I have been following the book Programming Robots with ROS and have been struggling with how the origin tag means in URDF files.

In the chapter 18, there is a snippet of URDF as the following:

  <link name="base_link">
    <visual>
      <geometry>
        <cylinder length="0.05" radius="0.1"/>
      </geometry>
      <material name="silver">
        <color rgba="0.75 0.75 0.75 1"/>
      </material>
      <origin rpy="0 0 0" xyz="0 0 0.025"/>
    </visual>
  </link>

The origin tag xyz = 0 0 0.025 puzzles me. The books says the 0.025 is meant to "... offset in z the point of reference for the base link from its default in the cylinder's center to its bottom." What I don't understand is that if we need to push the origin to the bottom, shouldn't we use -0.25? Why would increase the z value make the origin go down instead of going up?

What's more perplexing is that, later in the joint, it seems using a positive z value in origin actually makes the origin go up:

  <joint name="hip" type="continuous">
    <axis xyz="0 0 1"/>
    <parent link="base_link"/>
    <child link="torso"/>
    <origin rpy="0 0 0" xyz="0.0 0.0 0.05"/>
  </joint>

Here my understanding is that the z value 0.05 is meant to push the origin of the joint to be top of the base link so the next link can start there.

Why does positive value in link's origin push origin downward but push origin upward in joints?

The second snippet is a joint "hip" that connects base_link and torso. It's not the torso link itself. I don't quite ge

Please help me understand origin in URDF Hi folks, I have been following the book Programming Robots with ROS and have

Homebrew issue on macOS High Sierra (10.13.1 17B1003). #16953 Hi folks, I have been trying to install ROS on my Mac run

Unable to install fetch (sudo apt-get install ros-indigo-fetch*) Guys, I am trying to install the Fetch model on my mac

Guys,

I am having this issue where I can't use roslaunch command because every time I run something like:

roslaunch ros_robotics ddrobot_rviz.launch model:=dd_robot.urdf

it will error out with following message:

started roslaunch server http://localhost:34665/

SUMMARY

PARAMETERS
 * /joint_state_publisher/use_gui: True
 * /robot_description: <?xml version="1....
 * /rosdistro: kinetic
 * /rosversion: 1.12.7

NODES
  /
    joint_state_publisher (joint_state_publisher/joint_state_publisher)
    robot_state_publisher (robot_state_publisher/state_publisher)
    rviz (rviz/rviz)

auto-starting new master
process[master]: started with pid [2401]
ERROR: Unable to start XML-RPC server, port 11311 is already in use
Unhandled exception in thread started by <bound method XmlRpcNode.run of <rosgraph.xmlrpc.XmlRpcNode object at 0x7f38a45133d0>>
Traceback (most recent call last):
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rosgraph/xmlrpc.py", line 215, in run
    self._run()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rosgraph/xmlrpc.py", line 284, in _run
    self._run_init()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rosgraph/xmlrpc.py", line 234, in _run_init
    self.server = ThreadingXMLRPCServer((bind_address, port), log_requests)
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/rosgraph/xmlrpc.py", line 115, in __init__
    SimpleXMLRPCServer.__init__(self, addr, SilenceableXMLRPCRequestHandler, log_requests)
  File "/usr/lib/python2.7/SimpleXMLRPCServer.py", line 593, in __init__
    SocketServer.TCPServer.__init__(self, addr, requestHandler, bind_and_activate)
  File "/usr/lib/python2.7/SocketServer.py", line 417, in __init__
    self.server_bind()
  File "/usr/lib/python2.7/SocketServer.py", line 431, in server_bind
    self.socket.bind(self.server_address)
  File "/usr/lib/python2.7/socket.py", line 228, in meth
    return getattr(self._sock,name)(*args)
socket.error: [Errno 98] Address already in use
ERROR: could not contact master [http://localhost:11311//]
The traceback for the exception was written to the log file
[master] killing on exit

It seems that roslaunch tries to launch a master server while there is already one running in another terminal window.

Any idea how to resolve this?

Thanks!

As requested, this launch file might be helpful. That said, this issue is not specific to this particular launch file. Every launch file on my system errors out like this.

<launch>
  <!-- set parameter on Parameter Server -->
  <arg name="model" />
  <param name="robot_description"
    command="$(find xacro)/xacro.py '$(find ros_robotics)/urdf/$(arg model)'" />

  <!-- send joint values from gui -->
  <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
    <param name="use_gui" value="TRUE"/>
  </node>

  <!-- use joint positions to update tf -->
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher"/>

  <!-- visualize robot model in 3D -->
  <node name="rviz" pkg="rviz" type="rviz" args="-d $(find ros_robotics)/urdf.rviz" required="true" />

</launch>

Roy

Edit: @gvdhoorn

 roy@RoysMacUbuntu:~/catkin_ws/src/ros_robotics/urdf$ printenv | grep ROS
ROS_ROOT=/opt/ros/kinetic/share/ros
ROS_PACKAGE_PATH=/opt/ros/kinetic/share
ROS_MASTER_URI=http://localhost:11311//
ROS_HOSTNAME=localhostsource
ROSLISP_PACKAGE_DIRECTORIES=
ROS_DISTRO=kinetic

Awesome, it worked. Although the error messages printed out doesn't seem to be very relevant to the issue. Thank you v

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