To all,

I am trying to model a simple car wheel. I intended to use revolute2 so that the tire can roll and steer at the same time. I downloaded the gazebo model, "demojointstypes" from https://bitbucket.org/osrf/gazebo_models/src. I deleted most of the joints type except "Revolute2". But when I run the model, the model failed. The cylinder (revolute arm) link looks like dropped to below the ground. If I delete change the "revolute2" to "revolute" and deleted the associated tag, everything works with no steering.

How can I make the model to work? I suspect I did not have things turn on or my Gazebo version is outdated? I am using Gazebo 8.0.0

Thank you.

<sdf version="1.6">
<model name="joint_types_SDF">
    <link name="heavy_base">
        <pose>0 0 0.05 0 0 0</pose>
        <inertial>
            <mass>100</mass>
            <inertia>
                <ixx>8.4167</ixx>
                <ixy>0</ixy>
                <ixz>0</ixz>
                <iyy>40.417</iyy>
                <iyz>0</iyz>
                <izz>48.667</izz>
            </inertia>
        </inertial>
        <collision name="heavy_base_collision">
            <geometry>
                <box>
                    <size>2.2 1 0.1</size>
                </box>
            </geometry>
        </collision>
        <visual name="heavy_base_visual">
            <geometry>
                <box>
                    <size>2.2 1 0.1</size>
                </box>
            </geometry>
        </visual>
    </link>
    <link name="revolute2_base">
        <pose >-0.17 0 0.35 0 0 0</pose>
        <inertial>
            <inertia>
                <ixx>0.021667</ixx>
                <ixy>0</ixy>
                <ixz>0</ixz>
                <iyy>0.021667</iyy>
                <iyz>0</iyz>
                <izz>0.0016667</izz>
            </inertia>
        </inertial>
        <collision name="revolute2_base_collision">
            <geometry>
                <box>
                    <size>0.1 0.1 0.5</size>
                </box>
            </geometry>
        </collision>
        <visual name="revolute2_base_visual">
            <geometry>
                <box>
                    <size>0.1 0.1 0.5</size>
                </box>
            </geometry>
        </visual>
    </link>
    <link name="revolute2_arm">
        <pose >-0.06 -0.075 0.55 1.5708 0 0</pose>
        <inertial>
            <inertia>
                <ixx>0.0058333</ixx>
                <ixy>0</ixy>
                <ixz>0</ixz>
                <iyy>0.0058333</iyy>
                <iyz>0</iyz>
                <izz>0.00125</izz>
            </inertia>
            <pose >-0.1 -0.1 0.1 0 0 0</pose>
        </inertial>
        <collision name="revolute2_arm_collision">
            <geometry>
                <cylinder>
                    <radius>0.05</radius>
                    <length>0.25</length>
                </cylinder>
            </geometry>
        </collision>
        <visual name="revolute2_arm_visual">
            <geometry>
                <cylinder>
                    <radius>0.05</radius>
                    <length>0.25</length>
                </cylinder>
            </geometry>
        </visual>
    </link>

    <joint name="revolute2_base_to_heavy_base" type="fixed">
        <parent>heavy_base</parent>
        <child>revolute2_base</child>
    </joint>

    <joint name="revolute2_demo" type="revolute2">
        <parent>revolute2_base</parent>
        <child>revolute2_arm</child>
        <axis>
            <xyz>1 0 0</xyz>
        </axis>
        <axis2>
            <xyz>0 1 0</xyz>
        </axis2>            
        <pose>0 0 -0.075  0 0 0</pose>
    </joint>
</model>