A URDF (Unified Robot Description Format) model of Petoi's Quaddle — a 4-servo, omnidirectional quadruped robot kit for physical AI learning & experiments.
Try it now, no setup required: Quaddle robot simulator.
Watch it in action: Teach Quaddle How to Walk, Race with Pose-Controlled Teleoperation.
robot.urdf — the robot description (single file, no ROS package.xml/CMakeLists)
assets/ — STL meshes referenced by robot.urdf via package://assets/*.stl
All visual geometry is defined with package://assets/... mesh URIs. This is a bare
URDF, not a full ROS package — a viewer/tool that doesn't already resolve package://
paths (e.g. a generic URDF viewer, or Python tooling like yourdfpy/urdfpy) may need
either a ROS_PACKAGE_PATH entry that maps assets to this directory, or the mesh
paths rewritten to plain relative paths (assets/...).
The robot is modeled as a central body link with four identical leg assemblies —
left_front, right_front, right_back, left_back — each built from the same
per-leg joint pattern:
<side>_thigh (revolute) — the driven hip joint, connecting the leg assembly to
the body. One per leg; this is the actuated servo joint.<side>_motor_arm, <side>_leg, <side>_spring (revolute) — the
passive four-bar linkage that converts the single hip servo's rotation into
Quaddle's knee-lift walking gait (Petoi's "retro-mechanical" leg design — one motor
drives the full leg motion instead of a separate knee actuator).<side>_wheel, <side>_wheel_tip (continuous) — the rolling foot tip at
the end of each leg, enabling Quaddle's omnidirectional movement (walk, strafe,
spin in place) without extra actuators.<side>_knee, <side>_foot, body_collision, and the closing_* links —
fixed, zero-mass dummy frames used for collision geometry and linkage closure, not
physical parts.Totals: 46 links, 45 joints (16 revolute, 8 continuous, 21 fixed).
Any URDF-compatible viewer should work once mesh paths resolve correctly, for example:
# ROS 2 (if available)
ros2 launch urdf_tutorial display.launch.py model:=robot.urdf
# Or a standalone Python viewer
pip install yourdfpy
python3 -c "import yourdfpy; yourdfpy.URDF.load('robot.urdf').show()"
MIT — see LICENSE.
A URDF (Unified Robot Description Format) model of Petoi's Quaddle — a 4-servo, omnidirectional quadruped robot kit for physical AI learning & experiments.
Try it now, no setup required: Quaddle robot simulator.
Watch it in action: Teach Quaddle How to Walk, Race with Pose-Controlled Teleoperation.
robot.urdf — the robot description (single file, no ROS package.xml/CMakeLists)
assets/ — STL meshes referenced by robot.urdf via package://assets/*.stl
All visual geometry is defined with package://assets/... mesh URIs. This is a bare
URDF, not a full ROS package — a viewer/tool that doesn't already resolve package://
paths (e.g. a generic URDF viewer, or Python tooling like yourdfpy/urdfpy) may need
either a ROS_PACKAGE_PATH entry that maps assets to this directory, or the mesh
paths rewritten to plain relative paths (assets/...).
The robot is modeled as a central body link with four identical leg assemblies —
left_front, right_front, right_back, left_back — each built from the same
per-leg joint pattern:
<side>_thigh (revolute) — the driven hip joint, connecting the leg assembly to
the body. One per leg; this is the actuated servo joint.<side>_motor_arm, <side>_leg, <side>_spring (revolute) — the
passive four-bar linkage that converts the single hip servo's rotation into
Quaddle's knee-lift walking gait (Petoi's "retro-mechanical" leg design — one motor
drives the full leg motion instead of a separate knee actuator).<side>_wheel, <side>_wheel_tip (continuous) — the rolling foot tip at
the end of each leg, enabling Quaddle's omnidirectional movement (walk, strafe,
spin in place) without extra actuators.<side>_knee, <side>_foot, body_collision, and the closing_* links —
fixed, zero-mass dummy frames used for collision geometry and linkage closure, not
physical parts.Totals: 46 links, 45 joints (16 revolute, 8 continuous, 21 fixed).
Any URDF-compatible viewer should work once mesh paths resolve correctly, for example:
# ROS 2 (if available)
ros2 launch urdf_tutorial display.launch.py model:=robot.urdf
# Or a standalone Python viewer
pip install yourdfpy
python3 -c "import yourdfpy; yourdfpy.URDF.load('robot.urdf').show()"
MIT — see LICENSE.