Real-Time Physics Simulation Forum 2022-04-05T15:40:15+00:00 https://pybullet.org/Bullet/phpBB3/app.php/feed/topic/13414 2022-04-05T15:40:15+00:00 2022-04-05T15:40:15+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=43972#p43972 <![CDATA[Create joint between urdf-files]]> I want to programmatically create a fixed joint between multiple quadcopters, mid-flight, using pybullet.

I used the example for combining urdf-files and changed the imported urdf-files to my quadcopter model.
By doing so, I get an error in the createMultiBody method because createCollisionShape failed.

What do I have to change in my model and/or in the python code to achieve my described goal?


For the quadcopter model I used the following urdf:

Code: 

<?xml version="1.0" ?><robot name="cf2">  <properties arm="0.0397" kf="3.16e-10" km="7.94e-12" thrust2weight="2.25" max_speed_kmh="30" gnd_eff_coeff="11.36859" prop_radius="2.31348e-2" drag_coeff_xy="9.1785e-7" drag_coeff_z="10.311e-7" dw_coeff_1="2267.18" dw_coeff_2=".16" dw_coeff_3="-.11" />  <link name="base_link">     <inertial>      <origin rpy="0 0 0" xyz="0 0 0"/>      <mass value="0.027"/>      <inertia ixx="1.4e-5" ixy="0.0" ixz="0.0" iyy="1.4e-5" iyz="0.0" izz="2.17e-5"/>    </inertial>    <visual>      <origin rpy="0 0 55" xyz="0 0 0"/>      <geometry>        <mesh filename="./cf2.dae" scale=" 1 1 1"/>      </geometry>       <material name="grey">        <color rgba=".5 .5 .5 1"/>      </material>     </visual>    <collision>      <origin rpy="0 0 0" xyz="0 0 0"/>      <geometry>        <cylinder radius=".06" length=".025"/>      </geometry>    </collision>    </link>  <link name="prop0_link">    <inertial>      <origin rpy="0 0 0" xyz="0.028 0.028 0"/>      <mass value="0"/>      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>    </inertial>  </link>  <joint name="prop0_joint" type="fixed">    <parent link="base_link"/>    <child link="prop0_link"/>  </joint>  <link name="prop1_link">    <inertial>      <origin rpy="0 0 0" xyz="-0.028 0.028 0"/>      <mass value="0"/>      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>    </inertial>  </link>  <joint name="prop1_joint" type="fixed">    <parent link="base_link"/>    <child link="prop1_link"/>  </joint>  <link name="prop2_link">    <inertial>      <origin rpy="0 0 0" xyz="-0.028 -0.028 0"/>      <mass value="0"/>      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>    </inertial>  </link>  <joint name="prop2_joint" type="fixed">    <parent link="base_link"/>    <child link="prop2_link"/>  </joint>  <link name="prop3_link">    <inertial>      <origin rpy="0 0 0" xyz="0.028 -0.028 0"/>      <mass value="0"/>      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>    </inertial>  </link>  <joint name="prop3_joint" type="fixed">    <parent link="base_link"/>    <child link="prop3_link"/>  </joint>  <link name="center_of_mass_link">    <inertial>      <origin rpy="0 0 0" xyz="0 0 0"/>      <mass value="0"/>      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>    </inertial>  </link>  <joint name="center_of_mass_joint" type="fixed">    <parent link="base_link"/>    <child link="center_of_mass_link"/>  </joint></robot>
Thank you for any kind of help!

Statistics: Posted by rtpsf — Tue Apr 05, 2022 3:40 pm

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