Real-Time Physics Simulation Forum 2019-06-12T20:04:10+00:00 https://pybullet.org/Bullet/phpBB3/app.php/feed/topic/12693 2019-06-12T20:04:10+00:00 2019-06-12T20:04:10+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=42185#p42185 <![CDATA[Re: Free moving joint]]>

Statistics: Posted by pedro — Wed Jun 12, 2019 8:04 pm

]]> 2019-06-12T18:48:12+00:00 2019-06-12T18:48:12+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=42184#p42184 <![CDATA[Re: Free moving joint]]>
Hey,
How are you accessing joint configuration from URDF file. I am new to this and I am trying to make my base joint static. This base joint is obtained from URDF.

Thank you.
A joint is a connection between two links. If you mean that you want the connection of any two links to be static (no movement), you can use the type "fixed" in the URDF.

Statistics: Posted by pedro — Wed Jun 12, 2019 6:48 pm

]]> 2019-06-10T20:37:49+00:00 2019-06-10T20:37:49+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=42177#p42177 <![CDATA[Re: Free moving joint]]> How are you accessing joint configuration from URDF file. I am new to this and I am trying to make my base joint static. This base joint is obtained from URDF.

Thank you.

Statistics: Posted by usamarafiq93 — Mon Jun 10, 2019 8:37 pm

]]> 2019-06-05T19:40:18+00:00 2019-06-05T19:40:18+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=42166#p42166 <![CDATA[Free moving joint]]>
I am implementing a robot with a rope attached to the base. In the file description, instead of making it a soft body, I am trying to create several rigid bodies attached to each other in order to save some processing time. However, regardless of the joint type that I specify, the rope is rock solid.

Here is a snippet of the urdf

Code: 

  <link name="base_link">    <inertial>      <mass value="0.5"/>      <origin xyz="0 0 0"/>      <inertia ixx="0.0023" ixy="0.0" ixz="0.0" iyy="0.0023" iyz="0.0" izz="0.004"/>    </inertial>    <visual>      <origin rpy="0 0 0" xyz="0 0 0"/>      <geometry>        <mesh filename="base.obj" scale=".1 .1 .1"/>      </geometry>    </visual>    <collision>      <origin rpy="0 0 0" xyz="0 0 0"/>      <geometry>        <cylinder radius=".3" length=".3"/>      </geometry>    </collision>  </link>  <link name="rope">    <visual>      <geometry>        <cylinder length="0.3" radius="0.01"/>      </geometry>      <origin xyz="0 0 -0.15"/>      <material name="red">        <color rgba="0 0 .8 1"/>      </material>    </visual>    <collision>      <geometry>        <cylinder length="0.3" radius="0.01"/>      </geometry>      <origin xyz="0 0 -0.15"/>    </collision>    <inertial>      <mass value="0.05"/>      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>    </inertial>  </link>  <link name="rope2">    <visual>      <geometry>        <cylinder length="0.3" radius="0.01"/>      </geometry>      <origin xyz="0 0 -0.45"/>      <material name="red">        <color rgba="0.8 0 0 1"/>      </material>    </visual>    <collision>      <geometry>        <cylinder length="0.3" radius="0.01"/>      </geometry>      <origin xyz="0 0 -0.45"/>    </collision>    <inertial>      <mass value="0.05"/>      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>    </inertial>  </link>  <joint name="base_to_rope" type="floating">    <axis xyz="1 0 0"/>    <origin xyz="0.0 0.0 0.0"/>    <parent link="base_link"/>    <child link="rope"/>    <dynamics damping="0.0001" friction="0.0001"/>    <limit effort="200.0" lower="-30" upper="30" velocity="10"/>  </joint>  <joint name="rope_to_rope" type="floating">    <axis xyz="1 0 0"/>    <origin xyz="0.0 0.0 0.0"/>    <parent link="rope"/>    <child link="rope2"/>    <dynamics damping="0.0001" friction="0.0001"/>    <limit effort="1.0" lower="-30" upper="30" velocity="10"/>  </joint>

Statistics: Posted by pedro — Wed Jun 05, 2019 7:40 pm

]]>