Home | Tutorials | Wiki | Issues
Ask Your Question

ZdenekM's profile - activity

2016-03-11 02:13:48 -0500 commented answer Two robots in Gazebo, each with separate ROS

@nkoenig This is definitely question related to Gazebo. I already have working multimaster setup in the lab with two (real) robots. What I want is to simulate such setup. Right now I'm running two instances of Gazebo - each one with one of the robots and different ROS_MASTER_URI. But it would be great to have both robots simulated in one Gazebo instance (so they could collide with each other etc.). Is it clear now? Sorry for not being specific in the original question.

2016-03-10 06:17:58 -0500 commented answer Two robots in Gazebo, each with separate ROS

You are right. I should formulate my question more precisely... @nkoenig Is it possible to set ROS_MASTER_URI for a gazebo plugin?

2015-10-31 12:30:56 -0500 marked best answer CloudSim server

Is it possible to install CloudSim on some local server too? From tutorials it's not clear to me... Thanks.

2015-10-31 12:30:28 -0500 marked best answer Gazebo grass/pavement plane flickering

Hi all,

I built a simple model of outdoor environment using grass plane and pavement plane models (from DRC simulator database). My world file looks like this:

<?xml version='1.0'?>
<sdf version='1.4'>
  <world name='default'>
    <light name='sun' type='directional'>
      <cast_shadows>1</cast_shadows>
      <pose>0.000000 0.000000 10.000000 0.000000 0.000000 0.000000</pose>
      <diffuse>0.800000 0.800000 0.800000 1.000000</diffuse>
      <specular>0.200000 0.200000 0.200000 1.000000</specular>
      <attenuation>
        <range>1000.000000</range>
        <constant>0.900000</constant>
        <linear>0.010000</linear>
        <quadratic>0.001000</quadratic>
      </attenuation>
      <direction>0.500000 0.100000 -0.900000</direction>
    </light>

  <include>
    <uri>model://ground_plane</uri>
    <name>ground_plane</name>
    <pose>0 0 0   0 0 0</pose>
  </include>

      <physics type='ode'>
      <max_step_size>0.001000</max_step_size>
      <real_time_factor>1.000000</real_time_factor>
      <real_time_update_rate>1000.000000</real_time_update_rate>
      <gravity>0.000000 0.000000 -9.800000</gravity>
      <max_contacts>20</max_contacts>
    </physics>
    <scene>
      <ambient>0.400000 0.400000 0.400000 1.000000</ambient>
      <background>0.700000 0.700000 0.700000 1.000000</background>
      <shadows>1</shadows>
    </scene>

    <state world_name='default'>
      <sim_time>0 0</sim_time>
      <real_time>0 207512</real_time>
      <wall_time>1372662656 276170409</wall_time>
    </state>
    <gui fullscreen='0'>
      <camera name='user_camera'>
        <pose>3.082640 -6.458740 2.425810 0.000000 0.367643 2.028200</pose>
        <view_controller>orbit</view_controller>
      </camera>
    </gui>

  <!-- road segment ******************************    -->  
  <include>
    <uri>model://pavement_plane</uri>
    <name>pavement_plane_0</name>
    <pose>0 0 0   0 0 0</pose>
  </include>

  <include>
    <uri>model://grass_plane</uri>
    <name>grass_plane_0_0</name>
    <pose>0 -1 0   0 0 0</pose>
  </include>

  <include>
    <uri>model://grass_plane</uri>
    <name>grass_plane_0_1</name>
    <pose>0 2 0   0 0 0</pose>
  </include>

  <include>
    <uri>model://grass_plane</uri>
    <name>grass_plane_0_2</name>
    <pose>0 1 0   0 0 0</pose>
  </include>

  <include>
    <uri>model://grass_plane</uri>
    <name>grass_plane_0_3</name>
    <pose>0 -2 0   0 0 0</pose>
  </include>

etc...

When moving camera in Gazebo GUI planes are somehow flickering - at some position it looks good but in some other there are "holes". Also images published by robot cameras are flickering too.

See pict1, or pict2 (can't upload here because of karma).

I tried to downscale textures but it's same. Any ideas? Thanks in advance.

2015-10-31 12:12:26 -0500 marked best answer Modelling of sensor noise

Hi all,

I'm quite used to Gazebo in ROS Electric. In URDF, there is possibility to set desired level of Gaussian noise for laser scanner and IMU, distortion for camera etc. I went through specification of SDF and there are no such elements... So I'm wondering if it's going to be specified later or never. Thanks in advance.

2015-05-21 07:47:11 -0500 received badge  Famous Question (source)
2014-11-14 17:20:04 -0500 marked best answer slip1, slip2 in URDF

Hi all,

I'm working on URDF model of skid steering robot (Pioneer 3AT). There is new plugin for controlling this type of robot (see gazebo_plugins package) so, I can command robot from ROS and it moves. But I have problems with rotational movements - robot can't rotate. If I define wheels (collision geometry) as very thin cylinders and apply high torque it "somehow" rotates... If collision geometry is defined using mesh it's better but, robot jumps a bit.

The question is - how can I set slip1/slip2 (as setting this is recommended here) using URDF? As far as I know, URDF is translated into SDF so, I guess, it should be somehow possible. Thanks for hints in advance.

I'm using Gazebo 1.8 and gazeborospkgs for ROS integration.

2014-06-30 16:00:53 -0500 received badge  Notable Question (source)
2014-06-30 16:00:53 -0500 received badge  Famous Question (source)
2014-06-30 16:00:53 -0500 received badge  Popular Question (source)
2014-06-26 03:48:42 -0500 commented question Running Gazebo multiple times on one machine

I checked my setup.sh, corrected it by hand and now it works fine.

2014-06-26 03:08:23 -0500 commented question Running Gazebo multiple times on one machine
2014-06-26 03:05:45 -0500 asked a question Running Gazebo multiple times on one machine

Hi all,

I'm using ROS Hydro and Gazebo. The goal is to run more independent simulations at the same time by different users (on one machine). For each user there is unique port in GAZEBOMASTERURI. But when Gazebo is started using roslaunch it ignores this setting and then I'm getting "Unable to start server [Address already in use]" message. If it's started using only "gzserver" it works fine - on specified port. What's wrong?

2014-03-04 03:17:52 -0500 received badge  Citizen Patrol
2014-03-04 03:12:29 -0500 received badge  Famous Question (source)
2014-02-10 03:23:30 -0500 commented answer Gazebo on headless simulation server

Many thanks, I will check those links.

2014-02-10 02:13:41 -0500 received badge  Notable Question (source)
2014-02-06 10:37:52 -0500 received badge  Popular Question (source)
2014-02-04 06:58:26 -0500 commented answer Gazebo on headless simulation server

Thanks for hint. I didn't know there something like this.

2014-02-04 03:43:18 -0500 asked a question Gazebo on headless simulation server

Hello,

is there possibility to run Gazebo on headless server? I would like to setup complete ROS development server including Gazebo. The machine has graphic card with no OpenGL support. There is MESA so, for instance it's possible to run glxgears remotely (ssh -X). But Gazebo crashes with (RViZ also crashes):

X Error of failed request:  GLXBadDrawable
  Major opcode of failed request:  153 (GLX)
  Minor opcode of failed request:  5 (X_GLXMakeCurrent)
  Serial number of failed request:  31
  Current serial number in output stream:  31

It's possible to run gzserver like this:

user@server:~$ xvfb-run gzserver
Gazebo multi-robot simulator, version 1.9.3
Copyright (C) 2013 Open Source Robotics Foundation.
Released under the Apache 2 License.
http://gazebosim.org

Msg Waiting for master
Msg Connected to gazebo master @ http://127.0.0.1:12002
Msg Publicized address: xyz
Error [RenderEngine.cc:641] Unable to create glx visual
Warning [RenderEngine.cc:92] Unable to create X window. Rendering will be disabled

...but it would require installation of ROS/Gazebo also on client's machine which I would like to avoid and moreover it disables rendering (I can't use DepthCameraSensor). Any experience / tips will be highly appreciated :-)

UPDATE:

On server, I installed libgl1-mesa-swx11 (instead of libgl1-mesa-dri) and now it works somehow - it's possible to run gzserver on server or gazebo through X tunneling (this is painfully slow). Using webclient is probably a way to go.

2014-01-29 10:05:19 -0500 commented answer Reference paper for gazebo

Any news on this? Unfortunately, 2004 paper is bit out of date...

2014-01-23 13:43:52 -0500 received badge  Famous Question (source)
2014-01-07 12:13:00 -0500 commented question simulated environment

Btw, that would be great! Really looking forward to have such feature :)

2014-01-06 09:54:47 -0500 answered a question Programming Turtlebot in Gazebo

I guess you are working with Gazebo/ROS. Then you need to create node which will subscribe to Kinect data (sensor_msgs/PointCloud2, either real or simulated one) and then process point cloud somehow (take a look at PCL library). If you want to try something which works out-of-the-box you may try fake laser (creates 2D laser like data from Kinect) + gmapping (SLAM).

2014-01-01 09:31:50 -0500 commented question simulated environment

Please, can you reformulate your question? It is not clear what are you asking (at least for me). Thanks.

2013-12-11 03:26:26 -0500 received badge  Famous Question (source)
2013-12-05 05:08:42 -0500 commented answer How to simulate a Velodyne sensor?

I guess that modeling the Velodyne as a spinning vertical 2D laser would be even more realistic than using block laser.

2013-11-26 15:24:44 -0500 received badge  Student (source)
2013-11-26 15:24:27 -0500 received badge  Notable Question (source)
2013-11-25 11:35:19 -0500 received badge  Popular Question (source)
2013-11-22 04:01:20 -0500 received badge  Commentator
2013-11-22 04:01:20 -0500 commented question Gazebo vs. Bullet vs. Gpu

Btw, is there any other possibility to offload some work to GPU other than gpu laser? And what speedup does the gpu laser provide? I know, to much questions together... :) But they are somehow related.

2013-11-22 03:52:06 -0500 asked a question Gazebo vs. Bullet vs. Gpu

Hello all, as Gazebo 1.9 can be used with Bullet engine 2.8 (http://gazebosim.org/w/index.php?title=Tutorials/1.9/bullet) and this version should support some physics acceleration on GPU (http://bulletphysics.org/wordpress/?p=340) is there any way how to benefit from GPU acceleration in simulator? Is there any flag or something to enable it or will it require some significant update of Gazebo code?

2013-11-05 06:55:33 -0500 answered a question Skid Steer Drive Plugin unable to find joints when it is included in a sdf

You can try plugin from gazeborospkgs documented here: http://gazebosim.org/wiki/Tutorials/1.9/ROSMotorandSensorPlugins#SkidSteeringDrive. Let me know in case of any problems with this plugin.

2013-11-05 06:53:55 -0500 commented answer SkidSteerDrivePlugin

@Martí Morta - IRI You can find it in the package call gazeborospkgs. Documentation sits here: http://gazebosim.org/wiki/Tutorials/1.9/ROSMotorandSensorPlugins#SkidSteeringDrive

2013-11-04 10:33:14 -0500 marked best answer SkidSteerDrivePlugin

Hi all,

I'm trying to work with new skid steering drive plugin and URDF model of Pioneer 3AT. I included plugin to my URDF file, but still getting:

Error [Param.hh:249] Unable to set value [-nan -nan -nan 0 -0 0] for key[pose]
Error [Param.hh:249] Unable to set value [-nan] for key[ixx]
Error [Param.hh:249] Unable to set value [nan] for key[ixy]
Error [Param.hh:249] Unable to set value [-nan] for key[ixz]
Error [Param.hh:249] Unable to set value [-nan] for key[iyy]
Error [Param.hh:249] Unable to set value [-nan] for key[iyz]
Error [Param.hh:249] Unable to set value [nan] for key[izz]
Error [SkidSteerDrivePlugin.cc:51] Unable to find the right_front joint in model pioneer3at.
Error [SkidSteerDrivePlugin.cc:51] Unable to find the right_rear joint in model [INFO] [WallTime: 1372089505.447163] [0.489000] Spawn status: SpawnModel: Successfully spawned model
pioneer3at.
Error [SkidSteerDrivePlugin.cc:51] Unable to find the left_front joint in model pioneer3at.
Error [SkidSteerDrivePlugin.cc:51] Unable to find the left_rear joint in model pioneer3at.

This is how I included plugin:

<gazebo>
  <plugin name="SkidSteerDrivePlugin" filename="libSkidSteerDrivePlugin.so">
      <right_front>p3at_front_right_wheel_joint</right_front>
      <right_rear>p3at_back_right_wheel_joint</right_rear>
      <left_front>p3at_front_left_wheel_joint</left_front>
      <left_rear>p3at_back_left_wheel_joint</left_rear>
      <max_force>5.0</max_force>
  </plugin>
</gazebo>

ROS Groovy, Gazebo 1.8.6 compiled from source as well as gazeborospkgs.

I just briefly checked code of plugin and I'm not sure, but it looks like it searches for joints named "right_front" etc. and not for joints defined by these parameters. Am I right? Or could it be somehow related with NaN errors?

Thanks in advance.

Btw, what is prefered way to control robot from ROS? Use "pure" Gazebo plugin and ROS node for translating communication between Gazebo/ROS, or Gazebo plugin like those in gazeborospkgs? Second option looks better for me - are there any disadvantages?

2013-10-22 16:49:57 -0500 received badge  Famous Question (source)
2013-09-24 02:28:43 -0500 received badge  Popular Question (source)
2013-09-24 02:28:43 -0500 received badge  Notable Question (source)