Skip to content

Feature/gazebo caster wheel #118

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
masshu0504 wants to merge 5 commits into
base: develop
Choose a base branch
from
Draft

Feature/gazebo caster wheel #118

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
1b5fcbc
Draft .xacro file for caster wheel
Mar 31, 2026
473deb9
Draft .xacro file for caster wheel
Mar 31, 2026
3c9a52c
Merge branch 'feature/gazebo_caster_wheel' of https://github.com/RPI-…
masshu0504 Apr 3, 2026
5385386
Caster Wheel URDF add Parameters and include in
Apr 3, 2026
167be35
Merge branch 'feature/gazebo_caster_wheel' of https://github.com/RPI-…
Apr 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
332 changes: 332 additions & 0 deletions src/igvc_description/urdf/caster.urdf.xacro
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,332 @@
<?xml version="1.0" ?>
<robot name="igvc_description" xmlns:xacro="http://www.ros.org/wiki/xacro">

<!-- Import all Gazebo related items from .gazebo file -->
<xacro:include filename="$(find igvc_gazebo)/urdf/(gazebo stuff)" />

<!-- Constants -->
<xacro:property name="pi" value="3.1415926535897931" />

<!--base link values-->
<xacro:property name="base_link_length_width_height" value="_.___ _.___ _.___" />
<xacro:property name="base_link_length" value="_.___" />
<xacro:property name="base_link_width" value="_.___" />
<xacro:property name="base_link_height" value="_.___" />
<xacro:property name="base_link_mass" value="__"/> <!--__ kg-->

<!--left and right drive wheel values (both are same size)-->
<xacro:property name="drive_wheel_length" value="_.___" />
<xacro:property name="drive_wheel_radius" value="_.___" />
<xacro:property name="drive_wheel_mass" value="_"/> <!--_ kg-->

<!--left and right castor mount plate size (both are same size)-->
<xacro:property name="castor_mount_link_length_width_height" value="_.___ _.___ _.___" />
<xacro:property name="castor_mount_link_length" value="_.___" />
<xacro:property name="castor_mount_link_width" value="_.___" />
<xacro:property name="castor_mount_link_height" value="_.___" />
<xacro:property name="castor_mount_link_mass" value="_.___"/> <!--_.___ kg-->

<!--dummy link to give castors rotation about the Z axis-->
<xacro:property name="castor_mount_dummy_link_length" value="_.___" />
<xacro:property name="castor_mount_dummy_link_width" value="_.___" />
<xacro:property name="castor_mount_dummy_link_height" value="_.___" />
<xacro:property name="castor_mount_dummy_link_mass" value="_.___"/> <!--_.___ kg-->

<!-- left and right castor wheels (both are same size) -->
<xacro:property name="castor_wheel_length" value="_.___" />
<xacro:property name="castor_wheel_radius" value="_.___" />
<xacro:property name="castor_wheel_mass" value=""/> <!--_ kg-->

<!--dimensions of shaft which is tuned by A.M.P. servo motor -->
<xacro:property name="lms_rotating_shaft_length" value="_.___" />
<xacro:property name="lms_rotating_shaft_radius" value="_.___" />
<xacro:property name="lms_rotating_shaft_mass" value="_._"/> <!--_._ kg-->

<!--dimensions of plate on which the LMS sits -->
<xacro:property name="lms_plate_link_length_width_height" value="_.___ _.___ _.___" />
<xacro:property name="lms_plate_link_length" value="_.___" />
<xacro:property name="lms_plate_link_width" value="_.___" />
<xacro:property name="lms_plate_link_height" value="_.___" />
<xacro:property name="lms_plate_link_mass" value="_._"/> <!--_._ kg-->

<!--Box representing a collision space for the actual LMS. according to -->
<!--docs, using meshes for collisions is very computationally intensive, so-->
<!--it is much better to define collision space as a regular box. -->
<xacro:property name="lms_collision_space_length_width_height" value="_.___ _.___ _.___" />

<!--The dimensions of the aluminum extrusion holding the entire lms system -->
<xacro:property name="lms_structural_extrusion_link_length_width_height" value="_.___ _.___ _.___" />
<xacro:property name="lms_structural_extrusion_link_length" value="_.___" />
<xacro:property name="lms_structural_extrusion_link_width" value="_.___" />
<xacro:property name="lms_structural_extrusion_link_height" value="_.___" />
<xacro:property name="lms_structural_extrusion_link_mass" value="_._"/> <!--_._ kg-->

<!--Friction for joints-->
<xacro:property name="friction_val" value="_.___"/>


<!-- Macros -->
<xacro:macro name="box_link" params="link_name length width height material mass *origin">
<link name="${link_name}_link">
<!--If you do not explicitly specify a <collision> element. Gazebo will
treat your link as "invisible" to laser scanners and collision checking-->
<collision>
<geometry>
<box size="${length} ${width} ${height}"/>
</geometry>
<!-- line below allows us to insert:<origin rpy="${rpy}" xyz="${xyz}"/>-->
<xacro:insert_block name="origin" />
</collision>

<visual>
<geometry>
<!--box dimensions is Meters. L X W X H where the L X H is a ractange,
and the H extrudes it upwards -->
<box size="${length} ${width} ${height}"/>
</geometry>
<!-- line below allows us to insert:<origin rpy="${rpy}" xyz="${xyz}"/>-->
<xacro:insert_block name="origin" />
<material name="${material}"/>
</visual>


<inertial>
<!-- line below allows us to insert:<origin rpy="${rpy}" xyz="${xyz}"/>-->
<xacro:insert_block name="origin" />
<!--all blocks now need a 'mass' argument-->
<mass value="${mass}"/>
<!--This is the 3x3 inertial matrix. See: https://wiki.ros.org/urdf/XML/link -->
<!--where x=length; y=width; z=height. these lines of code came from
Emiliano Borghi's project-->
<inertia
ixx="${mass*(width*width+height*height)/12}"
ixy = "0"
ixz = "0"
iyy="${mass*(length*length+height*height)/12}"
iyz = "0"
izz="${mass*(length*length+height*height)/12}"/>
</inertial>

</link>
</xacro:macro>

<!-- Cylinder -->
<xacro:macro name="cylinder_link" params="link_name length radius material mass *origin">
<link name="${link_name}_link">
<!--If you do not explicitly specify a <collision> element. Gazebo will
treat your link as "invisible" to laser scanners and collision checking-->
<collision>
<geometry>
<cylinder length="${length}" radius="${radius}"/>
</geometry>
<xacro:insert_block name="origin" />
</collision>

<visual>
<geometry>
<cylinder length="${length}" radius="${radius}"/>
</geometry>
<!-- roll pitch and yaw will move the item in 3D space to arrange it how
we want it in relation to the origin. the XYZ is to move it around
the 3D space relative to the origin. Note that 1.57075 is pi/2 -->
<xacro:insert_block name="origin" />
<material name="${material}"/>
</visual>

<!--TODO-->
<inertial>
<!-- line below allows us to insert:<origin rpy="${rpy}" xyz="${xyz}"/>-->
<xacro:insert_block name="origin" />
<!--all blocks now need a 'mass' argument-->
<mass value="${mass}"/>

<!--This is the 3x3 inertial matrix. See: https://wiki.ros.org/urdf/XML/link -->
<inertia
ixx="${mass*(3*radius*radius+length*length)/12}"
ixy = "0"
ixz = "0"
iyy="${mass*(3*radius*radius+length*length)/12}"
iyz = "0"
izz="${mass*radius*radius/2}"
/>
</inertial>

</link>
</xacro:macro>

<!-- Continuous Joint -->
<xacro:macro name="continuous_joint" params="name rpy xyz parent child friction *origin">
<joint name="${name}_joint" type="continuous">
<axis rpy="${rpy}" xyz="${xyz}"/>
<parent link="${parent}_link"/>
<child link="${child}_link"/>
<!-- this is the point at which the two parts attach to one another -->
<xacro:insert_block name="origin" />
<!--This introduces friction so that continious joints don't spin indefinitly
damping is only used in Gazebo4 and earlier.... -->
<dynamics damping="0.0" friction="${friction}"/>
</joint>
</xacro:macro>

<!-- Fixed Joint -->
<xacro:macro name="fixed_joint" params="name parent child *origin">
<joint name="${name}_joint" type="fixed">
<parent link="${parent}_link"/>
<child link="${child}_link"/>
<!-- this is the point at which the two parts attach to one another -->
<xacro:insert_block name="origin" />
</joint>
</xacro:macro>


<!-- Link & Joint Definitions -->
<xacro:box_link link_name="base" length="${base_link_length}"
width="${base_link_width}"
height="${base_link_height}" material="white" mass="${base_link_mass}">
<!--origin rpy="0 0 0" xyz="-0.325 -0.1905 0.066"/-->
<origin rpy="0 0 0" xyz="-0.325 -0.1905 0.066"/>
</xacro:box_link>

<!--left_drive_wheel_link is a well named link :-) -->
<xacro:cylinder_link link_name="left_drive_wheel" length="${drive_wheel_length}" radius="${drive_wheel_radius}" material="black" mass="${drive_wheel_mass}">
<origin xyz="0 0 0" rpy="${pi/2} 0 0"/>
</xacro:cylinder_link>

<!-- -->
<xacro:continuous_joint name="base_to_left_drive_wheel" rpy="0 0 0" xyz="0 1 0" parent="base" child="left_drive_wheel"
friction="${friction_val}">
<origin xyz="-0.52835 0.037 -0.035"/>
</xacro:continuous_joint>

<!--right_drive_wheel_link is a well named link :-) -->
<xacro:cylinder_link link_name="right_drive_wheel" length="${drive_wheel_length}" radius="${drive_wheel_radius}" material="black" mass="${drive_wheel_mass}">
<origin xyz="0 0 0" rpy="${pi/2} 0 0"/>
</xacro:cylinder_link>

<!-- -->
<xacro:continuous_joint name="base_to_right_drive_wheel" rpy="0 0 0" xyz="0 1 0" parent="base" child="right_drive_wheel"
friction="${friction_val}">
<origin xyz="-0.52835 -0.421 -0.035"/>
</xacro:continuous_joint>
<!--left_caster_mount -->
<xacro:box_link link_name="left_castor_mount" length="${castor_mount_link_length}"
width="${castor_mount_link_width}"
height="${castor_mount_link_height}" material="white"
mass="${castor_mount_link_mass}">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:box_link>

<!--joint-->
<xacro:fixed_joint name="base_to_left_castor_mount" parent="base" child="left_castor_mount">
<origin xyz="-0.09445 -0.041 -0.03265"/>
</xacro:fixed_joint>


<!--left_caster_dummy to give the castor wheel rotation about the Z axis -->
<xacro:box_link link_name="left_castor_dummy" length="${castor_mount_dummy_link_length}"
width="${castor_mount_dummy_link_width}"
height="${castor_mount_dummy_link_height}" material="white"
mass="${castor_mount_dummy_link_mass}">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:box_link>

<!--joint between left castor mount and dummy link to allow rotation of castor wheel about z axis-->
<xacro:continuous_joint name="left_castor_mount_to_left_castor_dummy" rpy="0 0 0" xyz="0 0 1"
parent="left_castor_mount" child="left_castor_dummy" friction="${friction_val}">
<origin xyz="0.0 0.0 -0.01"/>
</xacro:continuous_joint>

<!--left_castor_wheel_link is a well named link :-) -->
<xacro:cylinder_link link_name="left_castor_wheel" length="${castor_wheel_length}" radius="${castor_wheel_radius}" material="Black" mass="${castor_wheel_mass}">
<origin xyz="0 0 0" rpy="${pi/2} 0 0"/>
</xacro:cylinder_link>

<!-- -->
<xacro:continuous_joint name="left_castor_dummy_to_left_castor_wheel" rpy="0 0 0" xyz="0 1 0"
parent="left_castor_dummy" child="left_castor_wheel" friction="${friction_val}">
<origin xyz="-0.037 0.0 -0.10785"/>
</xacro:continuous_joint>

<!-- Right Cast-->


<!--right_caster_plate_link is a well named link :-) -->
<xacro:box_link link_name="right_castor_mount" length="${castor_mount_link_length}"
width="${castor_mount_link_width}"
height="${castor_mount_link_height}" material="black"
mass="${castor_mount_link_mass}">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:box_link>

<!-- -->
<xacro:fixed_joint name="base_to_right_castor_mount" parent="base" child="right_castor_mount">
<origin xyz="-0.09445 -0.344 -0.03265"/>
</xacro:fixed_joint>

<!--right_caster_dummy to give the castor wheel rotation about the Z axis -->
<xacro:box_link link_name="right_castor_dummy" length="${castor_mount_dummy_link_length}"
width="${castor_mount_dummy_link_width}"
height="${castor_mount_dummy_link_height}" material="orange"
mass="${castor_mount_dummy_link_mass}">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:box_link>

<!--joint between right castor mount and dummy link to allow rotation of castor wheel about z axis-->
<xacro:continuous_joint name="right_castor_mount_to_right_castor_dummy" rpy="0 0 0" xyz="0 0 1"
parent="right_castor_mount" child="right_castor_dummy" friction="${friction_val}">
<origin xyz="0.0 0.0 -0.01"/>
</xacro:continuous_joint>


<!--right_castor_wheel_link is a well named link :-) -->
<xacro:cylinder_link link_name="right_castor_wheel" length="${castor_wheel_length}" radius="${castor_wheel_radius}"
material="Black" mass="${castor_wheel_mass}">
<origin xyz="0 0 0" rpy="${pi/2} 0 0"/>
</xacro:cylinder_link>

<!-- -->
<xacro:continuous_joint name="right_castor_dummy_to_right_castor_wheel" rpy="0 0 0" xyz="0 1 0"
parent="right_castor_dummy" child="right_castor_wheel" friction="${friction_val}">
<origin xyz="-0.037 0 -0.10785"/>
</xacro:continuous_joint>


<!--lms_structrual_extrusion is the aluminum extrusion that is supporting -->
<!-- the entire LMS structure. I put it here for aestetics. -->
<xacro:box_link link_name="lms_structural_extrusion" length="${lms_structural_extrusion_link_length}"
width="${lms_structural_extrusion_link_width}"
height="${lms_structural_extrusion_link_height}" material="white" mass="${lms_structural_extrusion_link_mass}">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:box_link>


<!-- -->
<xacro:fixed_joint name="base_link_to_lms_structural_extrusion" parent="base" child="lms_structural_extrusion">
<origin xyz="-0.3531 -0.1905 0.2173"/>
</xacro:fixed_joint>


<!--This is the rotating shaft on which the LMS sits, and which the servo -->
<!--motor rotates. -->
<xacro:cylinder_link link_name="lms_rotating_shaft" length="${lms_rotating_shaft_length}" radius="${lms_rotating_shaft_radius}" material="white" mass="${lms_rotating_shaft_mass}">
<origin xyz="0 0 0" rpy="0 0 0"/>
</xacro:cylinder_link>

<!-- This joint attaches the rotating_lms_shaft to the base link -->
<xacro:continuous_joint name="base_link_to_rotating_lms_shaft" rpy="0 0 0" xyz="0 0 1"
parent="base" child="lms_rotating_shaft" friction="${friction_val}">
<origin xyz="-0.2531 -0.1905 0.3195"/>
</xacro:continuous_joint>


<!--lms_plate is the plate onto which I mounted the lms :-) -->
<xacro:box_link link_name="lms_plate" length="${lms_plate_link_length}"
width="${lms_plate_link_width}"
height="${lms_plate_link_height}" material="white" mass="${lms_plate_link_mass}">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:box_link>

<!-- -->
<xacro:fixed_joint name="lms_rotating_shaft_to_lms_plate" parent="lms_rotating_shaft" child="lms_plate">
<origin xyz="-0.04905 0 0.120675"/>
</xacro:fixed_joint>
2 changes: 1 addition & 1 deletion src/igvc_description/urdf/robot.urdf.xacro
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@

<xacro:include filename="$(find igvc_description)/urdf/model.urdf.xacro"/>
<xacro:include filename="$(find igvc_description)/urdf/sensors.urdf.xacro"/>

<xacro:include filename="$(find igvc_description)/urdf/caster.urdf.xacro"/>
<xacro:include filename="$(find igvc_description)/control/bot.ros2_control.xacro" />

<xacro:bot_ros2_control name="IGVC_Bot" prefix="$(arg prefix)" use_mock_hardware="$(arg use_mock_hardware)"/>
Expand Down