Gazebo | Ignition | Community
Ask Your Question

liangfok's profile - activity

2017-09-28 07:06:50 -0500 received badge  Famous Question (source)
2016-11-03 14:47:09 -0500 commented answer Convert .urdf to .sdf or load .urdf

The latest command is: ``` gz sdf -p foo.urdf > foo.sdf ```

2016-10-20 14:31:50 -0500 received badge  Notable Question (source)
2016-10-20 14:31:50 -0500 received badge  Popular Question (source)
2016-10-19 12:46:39 -0500 asked a question Is there an Intermediate Representation of URDF and SDF?

When going from a URDF or SDF file to a simulated world, it is often useful for there to be an Intermediate Representation (IR). Benefits include:

  1. Decoupling the XML parsers from the methods that create the actual simulation objects.
  2. Performing some computation to fill in missing details in the IR like certain frame transformations, which joints form kinematic loops, etc.
  3. Identifying errors in the URDF and SDF specification so the system can fail fast.

Does an IR already exist between the URDF and SDF parsers and a Gazebo simulation? If so, where can I find it?

2016-05-27 03:16:57 -0500 received badge  Famous Question (source)
2016-03-21 04:46:44 -0500 received badge  Notable Question (source)
2016-03-08 05:35:57 -0500 received badge  Popular Question (source)
2016-03-07 08:41:25 -0500 asked a question Does Gazebo 7 Ignore the SDF Pose Element for Fixed Joints?

I believe the answer is yes but wanted to make sure. My SDF joint definition is as follows:

<joint name='myJoint' type='fixed'>
  <parent>parent_link</parent>
  <child>child_link</child>
  <pose>0 0 0 0 0 0</pose>
</joint>

I can change the <pose> element to be any arbitrary value and Gazebo 7 would show the robot as if the joint still had zero pose. Is this expected?

2015-05-24 21:39:41 -0500 received badge  Taxonomist
2015-05-15 05:29:45 -0500 received badge  Notable Question (source)
2015-05-15 05:29:45 -0500 received badge  Popular Question (source)
2015-02-04 05:34:46 -0500 commented answer Status of Bullet's soft-body dynamics integration

Any update on Gazebo's ability to simulate deformable objects?

2015-02-03 00:36:40 -0500 received badge  Notable Question (source)
2015-02-03 00:36:40 -0500 received badge  Popular Question (source)
2014-08-20 15:35:26 -0500 answered a question How to uninstall / Remove Gazebo 4 from ubuntu 12.04 precise ?

Try executing:

$ sudo apt-get remove gazebo4
2014-08-20 14:12:35 -0500 asked a question How do you downgrade from Gazebo 3.1 to Gazebo 3.0?

I have some simulations that used to work but are currently not working in Gazebo 3.1. I'd like to test whether the simulations worked when I was using Gazebo 3.0. How do I downgrade from Gazebo 3.1 to 3.0? I am using Ubuntu 12.04.4 64-bit.

2014-05-20 13:27:25 -0500 answered a question [SOLVED] How do you run the rqt_runtime_monitor?

I got it to work by executing:

rospack profile
2014-05-19 16:19:30 -0500 asked a question [SOLVED] How do you run the rqt_runtime_monitor?

When I try to run the rqt_runtime_monitor in standalone mode as described here, the following error occurs:

$ rosrun rqt_runtime_monitor rqt_runtime_monitor    
qt_gui_main() found no plugin matching "rqt_runtime_monitor"

Does anyone know how to fix this error?

I have rqt_runtime_monitor installed and the plugin is found:

$ rospack plugins --attrib=plugin rqt_gui
rqt_runtime_monitor /opt/ros/hydro/share/rqt_runtime_monitor/plugin.xml

I am using ROS Hydro on Ubuntu 12.04.4 64-bit desktop.

2014-04-15 14:02:40 -0500 commented question When exited gazebo via the quit menu the system does not shutdown completely.

I am running into the same problem. When I exit Gazebo, it usually stalls and eventually prints "escalating to SIGKILL on server" before exiting. This is a problem because it's preventing the destructor of a plugin from being called. I am using Gazebo 2.2.2 and ROS Groovy on Ubuntu 12.04.

2013-07-23 17:07:41 -0500 received badge  Famous Question (source)
2013-02-18 13:55:47 -0500 received badge  Popular Question (source)
2013-02-18 13:55:47 -0500 received badge  Famous Question (source)
2013-02-18 13:55:47 -0500 received badge  Notable Question (source)
2013-02-14 09:36:31 -0500 received badge  Popular Question (source)
2013-02-14 09:36:31 -0500 received badge  Notable Question (source)
2012-12-01 21:25:50 -0500 received badge  Nice Question (source)
2012-11-30 20:03:27 -0500 received badge  Student (source)
2012-11-29 15:50:45 -0500 asked a question Modeling Biarticular Transmission Constraint in Gazebo

I'm trying to simulate the Meka T2 humanoid torso that has a biarticular transmission joint constraint. Specifically the robot's hip and thorax joints are connected by a cable that's controlled by a single motor ensuring that the two joints have the same angle. How do I correctly model these types of joints in Gazebo and specify them in the SDF file?

2012-11-29 15:15:10 -0500 received badge  Editor (source)
2012-11-08 10:44:08 -0500 answered a question Gravity Disabled on Robot Pinned to World

The problem was fixed by specifying collision elements for each link in the robot. This is strange since collisions and dynamics should be decoupled. Should this be considered a bug?

2012-11-08 10:25:27 -0500 asked a question Gravity Disabled on Robot Pinned to World

I have a simple robot with four links and four revolute joints. The first joint is pinned to the world. When I run the simulation, the robot is not affected by gravity. I know gravity is enabled because when I drag another object like a box and drop it into the world, it falls down. I suspect that gravity is not affecting my four-link robot because it is pinned to the world. Could this be the case? How can I enable gravity for my robot?

Update: The problem was fixed by specifying collision elements for each link in the robot. This is strange since collisions and dynamics should be decoupled. Should this be considered a bug?