URDF model falls through the ground [closed]

asked 2019-12-06 09:48:38 -0600

simont gravatar image

updated 2019-12-06 11:09:17 -0600

gvdhoorn gravatar image

Dear all, I have the below URDF file.

This is a description for a inverse pendelum robot which I want to train in a simulation with AI. When I load this file with pybullet for the training, it falls down through the ground and won't stop falling.

Has anybody an idea what could be wrong with the URDF file?

If there are missing some important information please let me know.

Thanks a lot for your help guys?

<?xml version="1.0" ?>
<robot name="Cartpole">

  <joint name="Rotation" type="continuous">
    <parent link="Cart"/>
    <child link="Shaft"/>
    <origin rpy="0  0  0" xyz="0.0215  0.247   0.0435"/>
    <axis xyz="1  0  0"/>
    <limit effort="0.0" lower="0.0" upper="0.0" velocity="0.0"/>
  </joint>

  <joint name="Cart_joint" type="prismatic">
    <parent link="Base"/>
    <child link="Cart"/>
    <origin rpy="0  0  0" xyz="-0.04147 -0.31058  0.22851"/>
    <axis xyz="0 -1  0"/>
    <limit effort="0.0" lower="-0.23555" upper="0.23555" velocity="0.0"/>
  </joint>

  <joint name="Pole_Shaft" type="fixed">
    <parent link="Shaft"/>
    <child link="Pole"/>
    <origin rpy="0  0  0" xyz="0.0193  0      0.007"/>
    <axis xyz="0  0  0"/>
    <limit effort="0" lower="0" upper="0" velocity="0"/>
  </joint>

  <link name="Cart">
    <inertial>
      <mass value="0.4494280957660571"/>
      <origin rpy="0  0  0" xyz="0  0  0"/>
      <inertia ixx="0.034344216689805106" ixy="-0.0013555840592494157" ixz="0.005746023053830929" iyy="0.033575305370647346" iyz="0.007655119926892856" izz="0.0029338994617400297"/>
    </inertial>
    <collision name="Cart_collision">
      <origin rpy="0  0  0" xyz="-0.00606  0.24716  0.03996"/>
      <geometry>
        <mesh filename="package:///home/agent-pipeline/cad-assets/urdf_cadassets/meshes/CAD/Cart.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>
    <visual name="Cart_visual">
      <origin rpy="0  0  0" xyz="-0.00606  0.24716  0.03996"/>
      <geometry>
        <mesh filename="package:///home/agent-pipeline/cad-assets/urdf_cadassets/meshes/CAD/Cart.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </visual>
  </link>

  <link name="Shaft">
    <inertial>
      <mass value="0.024209988665072436"/>
      <origin rpy="0  0  0" xyz="0  0  0"/>
      <inertia ixx="0.00188987952436807" ixy="-1.1706804306416182e-05" ixz="5.008066577766269e-05" iyy="0.0017943029340322224" iyz="0.0004187314228447953" izz="0.00010090272031144335"/>
    </inertial>
    <collision name="Shaft_collision">
      <origin rpy="0  0  0" xyz="0.01237  0       0"/>
      <geometry>
        <mesh filename="package:///home/agent-pipeline/cad-assets/urdf_cadassets/meshes/CAD/Shaft.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>
    <visual name="Shaft_visual">
      <origin rpy="0  0  0" xyz="0.01237  0       0"/>
      <geometry>
        <mesh filename="package:///home/agent-pipeline/cad-assets/urdf_cadassets/meshes/CAD/Shaft.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </visual>
  </link>

  <link name="Pole">
    <inertial>
      <mass value="0.01797430178868597"/>
      <origin rpy="0  0  0" xyz="0  0  0"/>
      <inertia ixx ...
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Closed for the following reason question is off-topic or not relevant. Please see http://wiki.ros.org/Support for more details. by gvdhoorn
close date 2019-12-08 14:09:31.400422

Comments

Even thought you're using URDF, this does not sound like a ROS problem.

pybullet is part of Bullet, which is something we use in ROS, but is not part of ROS.

I would suggest to post your question on a forum focused on Bullet support.

gvdhoorn gravatar imagegvdhoorn ( 2019-12-06 11:16:05 -0600 )edit

Cross-posted to URDF model falls through the ground on Gazebo Answers.

gvdhoorn gravatar imagegvdhoorn ( 2019-12-08 02:31:25 -0600 )edit

I'm going to close this as it's already been cross-posted and it's not actually a ROS question.

gvdhoorn gravatar imagegvdhoorn ( 2019-12-08 14:09:23 -0600 )edit

Alright. Thankyou for your help.

simont gravatar imagesimont ( 2019-12-09 00:51:21 -0600 )edit