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I got model of hexapod in gazebo v11.10.2 with ro2-humble. I am controlling it with JTC controller. Model in gazebo is sliding and moving in place. Changing mu1 m2 coefficient in urdf does not seem to do any change (I can see them change in link inspector). Any change in behavior I can observe when I change mass or inertia of links. However when I increase mass the robot is totally unstable and it is flying whenever it touches ground plane. I also tried changing JTC PID gains, but with no luck.

Here is gif of a model slipping. Here is snipped from my tibia links:

Any suggestion are welcome.

<gazebo reference="tibia_link">
    <minDepth>0.005</minDepth>
    <mu1>150</mu1>
    <mu2>150</mu2>
    <material>Gazebo/Orange</material>
    <fdir1>1.0 0 0</fdir1>
</gazebo>
<link name="tibia_link">
    <inertial>
        <origin xyz="-0.0026216 -0.0028687 0.047559" rpy="0 0 0" />
        <mass value="0.07434" />
        <inertia ixx="0.0078" ixy="0" ixz="0" iyy="0.0072" iyz="0" izz="0.0021" />
    </inertial>
    <visual>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
            <mesh filename="tibia_link.STL" />
        </geometry>
        <material name="">
            <color rgba="1 1 1 1" />
        </material>
    </visual>
    <collision>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
            <mesh filename="tibia_link.STL" />
        </geometry>
    </collision>
</link>
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  • $\begingroup$ Which gazebo version, which ROS distro are you using? $\endgroup$ Dec 6, 2023 at 15:04
  • $\begingroup$ ros2 humble with gazebo 11.10.2 $\endgroup$ Dec 6, 2023 at 15:37

1 Answer 1

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Exploding models usually come from wrong configuration of mass and inerta (they are not independent!). Visualize them with View->Inertias: The pink boxes should align with your mesh, otherwise you have misparameterized it. As a consequence, you cannot just change the mass significantly without changing the inertia. Setting the inertia of some "minor" parts to zero also has bad effects, unless they have fixed joints (gazebo with default settings reduces them to one fixed link)

If this is fine, visualize the contact points with View->Contacts. Are they stable when the tips touch the ground?

I'm almost sure that this has nothing to do with JTC.

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