urdfgenpy

Programmatically generate URDF and Xacro robot description files in pure Python.

urdfgenpy lets you build valid robot description files from Python objects - links, joints, geometry, inertia - and export them to .urdf or .xacro without writing a single line of XML by hand.

Key features:

• No XML - describe your robot entirely in Python

• Automatic inertia tensors from geometry primitives (Box, Cylinder, Sphere)

• URDF and Xacro export with a single robot.save() call

• Kinematic tree visualisation with colour-coded joint types

Install with pip:

pip install urdfgenpy

from urdfgenpy import (
   Box,
   Collision,
   Cylinder,
   Inertial,
   Joint,
   JointLimit,
   Link,
   Material,
   Origin,
   Robot,
   Visual,
)

grey = Material("grey", rgba=(0.5, 0.5, 0.5, 1.0))
blue = Material("blue", rgba=(0.0, 0.3, 0.8, 1.0))

# Base link
base_box = Box(length=0.2, width=0.2, height=0.05)
base_link = Link("base_link")
base_link.add_visual(Visual(geometry=base_box, origin=Origin.above(base_box), material=grey))
base_link.add_collision(Collision(geometry=base_box, origin=Origin.above(base_box)))
base_link.set_inertial(Inertial.from_geometry(mass=1.0, geometry=base_box))

# Shoulder link
shoulder_cyl = Cylinder(radius=0.04, length=0.15)
shoulder_link = Link("shoulder_link")
shoulder_link.add_visual(Visual(geometry=shoulder_cyl, origin=Origin.above(shoulder_cyl), material=blue))
shoulder_link.add_collision(Collision(geometry=shoulder_cyl, origin=Origin.above(shoulder_cyl)))
shoulder_link.set_inertial(Inertial.from_geometry(mass=0.5, geometry=shoulder_cyl))

# Joint
joint = Joint(
   name="base_shoulder_joint",
   joint_type="revolute",
   parent="base_link",
   child="shoulder_link",
   origin=Origin(xyz=(0.0, 0.0, 0.05)),
   axis=(0.0, 0.0, 1.0),
   limit=JointLimit(lower=-3.14, upper=3.14, effort=50.0, velocity=2.0),
)

robot = Robot("my_robot")
for mat in [grey, blue]:
   robot.add_material(mat)
for link in [base_link, shoulder_link]:
   robot.add_link(link)
robot.add_joint(joint)

robot.save("my_robot.urdf")
robot.print_tree()

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License

urdfgenpy is made available under the MIT License. For more details, see LICENSE.