Gazebo | Ignition | Community
Ask Your Question
0

revolute2 joints are not holding high mass links

asked 2014-07-01 12:51:49 -0500

jitrc gravatar image

On adding high mass in inertial to the chassis of utility cart model the chassis is dropping to ground as the joints to the wheels are of type revolute2. If I change them to revolute joints the chassis stays in position.

http://pastebin.com/PXY2JWSv

Am I missing something. I faced similar problem while adding 2 revolute joints in series too for a car's steering and wheel rotation. image description

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
0

answered 2014-07-01 17:18:19 -0500

nkoenig gravatar image

I was unable to reproduce the problem. I'm running Gazebo 3.1, and I used the following SDF file (which is your model minus the plugin):

<?xml version="1.0" ?>
<sdf version="1.4">
  <world name="default">
    <!-- A global light source -->
    <include>
      <uri>model://sun</uri>
    </include>
    <!-- A ground plane -->
    <include>
      <uri>model://ground_plane</uri>
    </include>


    <model name="car">
      <link name="chassis">
        <pose>0 0 0.3 0 0 0</pose>
        <inertial>
          <mass>720.0</mass>
          <inertia>
            <ixx>140</ixx>
            <ixy>0.0</ixy><iyy>550</iyy>
            <ixz>0.0</ixz><iyz>0.0</iyz><izz>550</izz>
          </inertia>
          <pose>0.1 0 0.4  0 0 0</pose>
        </inertial>
        <collision name="collision">
          <geometry>
            <box><size>2.0 1.0 0.2</size></box>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <box><size>2.0 1.0 0.2</size></box>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Green</name>
            </script>
          </material>
        </visual>
      </link>
      <link name="front_left_wheel">
        <pose>0.8 0.6 0.3 0 1.5707 1.5707</pose>
        <collision name="collision">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Black</name>
            </script>
          </material>
        </visual>
      </link>
      <link name="front_right_wheel">
        <pose>0.8 -0.6 0.3 0 1.5707 1.5707</pose>
        <collision name="collision">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Black</name>
            </script>
          </material>
        </visual>
      </link>
      <link name="back_right_wheel">
        <pose>-0.8 -0.6 0.3 0 1.5707 1.5707</pose>
        <collision name="collision">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Black</name>
            </script>
          </material>
        </visual>
      </link>
      <link name="back_left_wheel">
        <pose>-0.8 0.6 0.3 0 1.5707 1.5707</pose>
        <collision name="collision">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <cylinder><radius>0.3</radius><length>0.1</length></cylinder>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Black</name>
            </script>
          </material>
        </visual>
      </link>
      <link name="gas_pedal">
        <pose>0.3 0.1 0.5 0 0 0</pose>
        <collision name="collision">
          <geometry>
            <box><size>0.1 0.1 0.1</size></box>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <box><size>0.1 0.1 0.1</size></box>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Red</name>
            </script>
          </material>
        </visual>
      </link>
      <link name="brake_pedal">
        <pose>0.3 0.25 0.5 0 0 0</pose>
        <collision name="collision ...
(more)
edit flag offensive delete link more

Comments

Just checked now, the problem is fixed in Gazebo 3. I was using 1.9.5, the problem persists in 2.2 also. Thanks. I would try to add suspension to the car using prismatic joints

jitrc gravatar imagejitrc ( 2014-07-02 00:59:59 -0500 )edit

Actually It is still not working in Gazebo 3.0. Gazebo choose a different sdf file as 3.0 supports sdf 1.5. I added inertia to that file also and the problem remains

jitrc gravatar imagejitrc ( 2014-07-02 04:08:22 -0500 )edit

Take a look at the vehicle models (including one with suspension) in the following pull request: https://bitbucket.org/osrf/gazebo_models/pull-request/82/vehicle-models-with-steering-and-soft

scpeters gravatar imagescpeters ( 2014-07-03 12:27:02 -0500 )edit

That would solve everything, thanks. I would also make our model and plugin available in public as soon as I get it working. Currently we are developing it at aurobots.com

jitrc gravatar imagejitrc ( 2014-07-04 11:56:43 -0500 )edit

If you want to make your model publically available, please submit a pull request to https://bitbucket.org/osrf/gazebo_models. We love new models!

nkoenig gravatar imagenkoenig ( 2014-07-09 11:47:11 -0500 )edit
Login/Signup to Answer

Question Tools

Stats

Asked: 2014-07-01 12:51:49 -0500

Seen: 700 times

Last updated: Jul 01 '14