yourdfpy package

Submodules

yourdfpy.urdf module

class yourdfpy.urdf.Actuator(name: str, mechanical_reduction: Union[float, NoneType] = None, hardware_interfaces: List[str] = <factory>)[source]

Bases: object

hardware_interfaces: List[str]
mechanical_reduction: float | None = None
name: str
class yourdfpy.urdf.Box(size: numpy.ndarray)[source]

Bases: object

size: ndarray
class yourdfpy.urdf.Calibration(rising: float | NoneType = None, falling: float | NoneType = None)[source]

Bases: object

falling: float | None = None
rising: float | None = None
class yourdfpy.urdf.Collision(name: str, origin: numpy.ndarray | NoneType = None, geometry: yourdfpy.urdf.Geometry = None)[source]

Bases: object

geometry: Geometry = None
name: str
origin: ndarray | None = None
class yourdfpy.urdf.Color(rgba: numpy.ndarray)[source]

Bases: object

rgba: ndarray
class yourdfpy.urdf.Cylinder(radius: float, length: float)[source]

Bases: object

length: float
radius: float
class yourdfpy.urdf.Dynamics(damping: float | NoneType = None, friction: float | NoneType = None)[source]

Bases: object

damping: float | None = None
friction: float | None = None
class yourdfpy.urdf.Geometry(box: yourdfpy.urdf.Box | NoneType = None, cylinder: yourdfpy.urdf.Cylinder | NoneType = None, sphere: yourdfpy.urdf.Sphere | NoneType = None, mesh: yourdfpy.urdf.Mesh | NoneType = None)[source]

Bases: object

box: Box | None = None
cylinder: Cylinder | None = None
mesh: Mesh | None = None
sphere: Sphere | None = None
class yourdfpy.urdf.Inertial(origin: numpy.ndarray | NoneType = None, mass: float | NoneType = None, inertia: numpy.ndarray | NoneType = None)[source]

Bases: object

inertia: ndarray | None = None
mass: float | None = None
origin: ndarray | None = None
class yourdfpy.urdf.Joint(name: str, type: str = None, parent: str = None, child: str = None, origin: numpy.ndarray = None, axis: numpy.ndarray = None, dynamics: yourdfpy.urdf.Dynamics | NoneType = None, limit: yourdfpy.urdf.Limit | NoneType = None, mimic: yourdfpy.urdf.Mimic | NoneType = None, calibration: yourdfpy.urdf.Calibration | NoneType = None, safety_controller: yourdfpy.urdf.SafetyController | NoneType = None)[source]

Bases: object

axis: ndarray = None
calibration: Calibration | None = None
child: str = None
dynamics: Dynamics | None = None
limit: Limit | None = None
mimic: Mimic | None = None
name: str
origin: ndarray = None
parent: str = None
safety_controller: SafetyController | None = None
type: str = None
class yourdfpy.urdf.Limit(effort: float | NoneType = None, velocity: float | NoneType = None, lower: float | NoneType = None, upper: float | NoneType = None)[source]

Bases: object

effort: float | None = None
lower: float | None = None
upper: float | None = None
velocity: float | None = None

Bases: object

collisions: List[Collision]
inertial: Inertial | None = None
name: str
visuals: List[Visual]
class yourdfpy.urdf.Material(name: str | NoneType = None, color: yourdfpy.urdf.Color | NoneType = None, texture: yourdfpy.urdf.Texture | NoneType = None)[source]

Bases: object

color: Color | None = None
name: str | None = None
texture: Texture | None = None
class yourdfpy.urdf.Mesh(filename: str, scale: float | numpy.ndarray | NoneType = None)[source]

Bases: object

filename: str
scale: float | ndarray | None = None
class yourdfpy.urdf.Mimic(joint: str, multiplier: float | NoneType = None, offset: float | NoneType = None)[source]

Bases: object

joint: str
multiplier: float | None = None
offset: float | None = None
class yourdfpy.urdf.Robot(name: str, links: List[yourdfpy.urdf.Link] = <factory>, joints: List[yourdfpy.urdf.Joint] = <factory>, materials: List[yourdfpy.urdf.Material] = <factory>, transmission: List[str] = <factory>, gazebo: List[str] = <factory>)[source]

Bases: object

gazebo: List[str]
joints: List[Joint]
materials: List[Material]
name: str
transmission: List[str]
class yourdfpy.urdf.SafetyController(soft_lower_limit: float | NoneType = None, soft_upper_limit: float | NoneType = None, k_position: float | NoneType = None, k_velocity: float | NoneType = None)[source]

Bases: object

k_position: float | None = None
k_velocity: float | None = None
soft_lower_limit: float | None = None
soft_upper_limit: float | None = None
class yourdfpy.urdf.Sphere(radius: float)[source]

Bases: object

radius: float
class yourdfpy.urdf.Texture(filename: str)[source]

Bases: object

filename: str
class yourdfpy.urdf.Transmission(name: str, type: Union[str, NoneType] = None, joints: List[yourdfpy.urdf.TransmissionJoint] = <factory>, actuators: List[yourdfpy.urdf.Actuator] = <factory>)[source]

Bases: object

actuators: List[Actuator]
joints: List[TransmissionJoint]
name: str
type: str | None = None
class yourdfpy.urdf.TransmissionJoint(name: str, hardware_interfaces: List[str] = <factory>)[source]

Bases: object

hardware_interfaces: List[str]
name: str
class yourdfpy.urdf.URDF(robot: Robot | None = None, build_scene_graph: bool = True, build_collision_scene_graph: bool = False, load_meshes: bool = True, load_collision_meshes: bool = False, filename_handler=None, mesh_dir: str = '', force_mesh: bool = False, force_collision_mesh: bool = True)[source]

Bases: object

property actuated_dof_indices

List of DOF indices per actuated joint. Can be used to reference configuration.

Returns:

List of DOF indices per actuated joint.

Return type:

list[list[int]]

property actuated_joint_indices

List of indices of all joints that are actuated, i.e., not of type mimic or fixed.

Returns:

List of indices of actuated joints.

Return type:

list[int]

property actuated_joint_names

List of names of actuated joints. This excludes mimic and fixed joints.

Returns:

List of names of actuated joints of the URDF model.

Return type:

list[str]

property actuated_joints

List of actuated joints. This excludes mimic and fixed joints.

Returns:

List of actuated joints of the URDF model.

Return type:

list[Joint]

Name of URDF base/root link.

Returns:

Name of base link of URDF model.

Return type:

str

property center_cfg

Return center configuration of URDF model by using the average of each joint’s limits if present, otherwise zero.

Returns:

Default configuration of URDF model.

Return type:

(n), float

property cfg

Current configuration.

Returns:

Current configuration of URDF model.

Return type:

np.ndarray

clear_errors()[source]

Clear the validation error log.

property collision_scene: Scene

A scene object representing the <collision> elements of the URDF model

Returns:

A trimesh scene object.

Return type:

trimesh.Scene

contains(key, value, element=None) → bool[source]

Checks recursively whether the URDF tree contains the provided key-value pair.

Parameters:

  • key (str) – A key.

  • value (str) – A value.

  • element (etree.Element, optional) – The XML element from which to start the recursive search. None means URDF root. Defaults to None.

Returns:

Whether the key-value pair was found.

Return type:

bool

property errors: list

A list with validation errors.

Returns:

A list of validation errors.

Return type:

list

get_transform(frame_to, frame_from=None, collision_geometry=False)[source]

Get the transform from one frame to another.

Parameters:

  • frame_to (str) – Node name.

  • frame_from (str, optional) – Node name. If None it will be set to self.base_frame. Defaults to None.

  • collision_geometry (bool, optional) – Whether to use the collision geometry scene graph (instead of the visual geometry). Defaults to False.

Raises:

ValueError – Raised if scene graph wasn’t constructed during intialization.

Returns:

Homogeneous transformation matrix

Return type:

(4, 4) float

property joint_map: dict

A dictionary mapping joint names to joint objects.

Returns:

Mapping from joint name (str) to Joint.

Return type:

dict

property joint_names

List of joint names.

Returns:

List of joint names of the URDF model.

Return type:

list[str]

A dictionary mapping link names to link objects.

Returns:

Mapping from link name (str) to Link.

Return type:

dict

static load(fname_or_file, **kwargs)[source]

Load URDF file from filename or file object.

Parameters:

  • fname_or_file (str or file object) – A filename or file object, file-like object, stream representing the URDF file.

  • **build_scene_graph (bool, optional) – Wheter to build a scene graph to enable transformation queries and forward kinematics. Defaults to True.

  • **build_collision_scene_graph (bool, optional) – Wheter to build a scene graph for <collision> elements. Defaults to False.

  • **load_meshes (bool, optional) – Whether to load the meshes referenced in the <mesh> elements. Defaults to True.

  • **load_collision_meshes (bool, optional) – Whether to load the collision meshes referenced in the <mesh> elements. Defaults to False.

  • **filename_handler ([type], optional) – Any function f(in: str) -> str, that maps filenames in the URDF to actual resources. Can be used to customize treatment of package:// directives or relative/absolute filenames. Defaults to None.

  • **mesh_dir (str, optional) – A root directory used for loading meshes. Defaults to “”.

  • **force_mesh (bool, optional) – Each loaded geometry will be concatenated into a single one (instead of being turned into a graph; in case the underlying file contains multiple geometries). This might loose texture information but the resulting scene graph will be smaller. Defaults to False.

  • **force_collision_mesh (bool, optional) – Same as force_mesh, but for collision scene. Defaults to True.

Raises:

ValueError – If filename does not exist.

Returns:

URDF model.

Return type:

yourdfpy.URDF

property num_actuated_joints

Number of actuated joints.

Returns:

Number of actuated joints.

Return type:

int

property num_dofs

Number of degrees of freedom of actuated joints. Depending on the type of the joint, the number of DOFs might vary.

Returns:

Degrees of freedom.

Return type:

int

property scene: Scene

A scene object representing the URDF model.

Returns:

A trimesh scene object.

Return type:

trimesh.Scene

show(collision_geometry=False, callback=None)[source]

Open a simpler viewer displaying the URDF model.

Parameters:

collision_geometry (bool, optional) – Whether to display the <collision> or <visual> elements. Defaults to False.

split_along_joints(joint_type='floating', **kwargs)[source]

Split URDF model along a particular joint type. The result is a set of URDF models which together compose the original URDF.

Parameters:

  • joint_type (str, or list[str], optional) – Type of joint to use for splitting. Defaults to “floating”.

  • **kwargs – Arguments delegated to URDF constructor of new URDF models.

Returns:

A list of tuples (np.ndarray, yourdfpy.URDF) whereas each homogeneous 4x4 matrix describes the root transformation of the respective URDF model w.r.t. the original URDF.

Return type:

list[(np.ndarray, yourdfpy.URDF)]

update_cfg(configuration)[source]

Update joint configuration of URDF; does forward kinematics.

Parameters:

configuration (dict, list[float], tuple[float] or np.ndarray) – A mapping from joints or joint names to configuration values, or a list containing a value for each actuated joint.

Raises:

  • ValueError – Raised if dimensionality of configuration does not match number of actuated joints of URDF model.

  • TypeError – Raised if configuration is neither a dict, list, tuple or np.ndarray.

validate(validation_fn=None) → bool[source]

Validate URDF model.

Parameters:

validation_fn (function, optional) – A function f(list[yourdfpy.URDFError]) -> bool. None uses the strict handler (any error leads to False). Defaults to None.

Returns:

Whether the model is valid.

Return type:

bool

validate_filenames()[source]
write_xml()[source]

Write URDF model to an XML element hierarchy.

Returns:

XML data.

Return type:

etree.ElementTree

write_xml_file(fname)[source]

Write URDF model to an xml file.

Parameters:

fname (str) – Filename of the file to be written. Usually ends in .urdf.

write_xml_string(**kwargs)[source]

Write URDF model to a string.

Returns:

String of the xml representation of the URDF model.

Return type:

str

property zero_cfg

Return the zero configuration.

Returns:

The zero configuration.

Return type:

np.ndarray

exception yourdfpy.urdf.URDFAttributeValueError(msg)[source]

Bases: URDFError

Raised when attribute value is not contained in the set of allowed values.

exception yourdfpy.urdf.URDFBrokenRefError(msg)[source]

Bases: URDFError

Raised when a referenced object is not found in the scope.

exception yourdfpy.urdf.URDFError(msg)[source]

Bases: Exception

General URDF exception.

exception yourdfpy.urdf.URDFIncompleteError(msg)[source]

Bases: URDFError

Raised when needed data for an object isn’t there.

exception yourdfpy.urdf.URDFMalformedError(msg)[source]

Bases: URDFError

Raised when data is found to be corrupted in some way.

exception yourdfpy.urdf.URDFSaveValidationError(msg)[source]

Bases: URDFError

Raised when XML validation fails when saving.

exception yourdfpy.urdf.URDFUnsupportedError(msg)[source]

Bases: URDFError

Raised when some unexpectedly unsupported feature is found.

class yourdfpy.urdf.Visual(name: str | NoneType = None, origin: numpy.ndarray | NoneType = None, geometry: yourdfpy.urdf.Geometry | NoneType = None, material: yourdfpy.urdf.Material | NoneType = None)[source]

Bases: object

geometry: Geometry | None = None
material: Material | None = None
name: str | None = None
origin: ndarray | None = None
yourdfpy.urdf.apply_visual_color(geom: Trimesh, visual: Visual, material_map: Dict[str, Material]) → None[source]

Apply the color of the visual material to the mesh.

Parameters:

  • geom – Trimesh to color.

  • visual – Visual description from XML.

  • material_map – Dictionary mapping material names to their definitions.

yourdfpy.urdf.filename_handler_absolute2relative(fname, dir)[source]

A filename handler that turns an absolute file name into a relative one.

Parameters:

  • fname (str) – A file name.

  • dir (str) – A directory.

Returns:

The file name relative to the directory.

Return type:

str

yourdfpy.urdf.filename_handler_add_prefix(fname, prefix)[source]

A filename handler that adds a prefix.

Parameters:

  • fname (str) – A file name.

  • prefix (str) – A prefix.

Returns:

Prefix plus file name.

Return type:

str

yourdfpy.urdf.filename_handler_ignore_directive(fname)[source]

A filename handler that removes anything before (and including) ‘://’.

Parameters:

fname (str) – A file name.

Returns:

The file name without the prefix.

Return type:

str

yourdfpy.urdf.filename_handler_ignore_directive_package(fname)[source]

A filename handler that removes the ‘package://’ directive and the package it refers to. It subsequently calls filename_handler_ignore_directive, i.e., it removes any other directive.

Parameters:

fname (str) – A file name.

Returns:

The file name without ‘package://’ and the package name.

Return type:

str

yourdfpy.urdf.filename_handler_magic(fname, dir)[source]

A magic filename handler.

Parameters:

  • fname (str) – A file name.

  • dir (str) – A directory.

Returns:

The file name that exists or the input if nothing is found.

Return type:

str

yourdfpy.urdf.filename_handler_meta(fname, filename_handlers)[source]

A filename handler that calls other filename handlers until the resulting file name points to an existing file.

Parameters:

  • fname (str) – A file name.

  • filename_handlers (list(fn)) – A list of function pointers to filename handlers.

Returns:

The resolved file name that points to an existing file or the input if none of the files exists.

Return type:

str

yourdfpy.urdf.filename_handler_null(fname)[source]

A lazy filename handler that simply returns its input.

Parameters:

fname (str) – A file name.

Returns:

Same file name.

Return type:

str

yourdfpy.urdf.filename_handler_relative(fname, dir)[source]

A filename handler that joins a file name with a directory.

Parameters:

  • fname (str) – A file name.

  • dir (str) – A directory.

Returns:

The directory joined with the file name.

Return type:

str

yourdfpy.urdf.filename_handler_relative_to_urdf_file(fname, urdf_fname)[source]
yourdfpy.urdf.filename_handler_relative_to_urdf_file_recursive(fname, urdf_fname, level=0)[source]
yourdfpy.urdf.validation_handler_strict(errors)[source]

A validation handler that does not allow any errors.

Parameters:

errors (list[yourdfpy.URDFError]) – List of errors.

Returns:

Whether any errors were found.

Return type:

bool

yourdfpy.viz module

Script for visualizing a robot from a URDF.

yourdfpy.viz.generate_joint_limit_trajectory(urdf_model, loop_time)[source]

Generate a trajectory for all actuated joints that interpolates between joint limits. For continuous joint interpolate between [0, 2 * pi].

Parameters:

  • urdf_model (yourdfpy.URDF) – _description_

  • loop_time (float) – Time in seconds to loop through the trajectory.

Returns:

A dictionary over all actuated joints with list of configuration values.

Return type:

dict

yourdfpy.viz.main(args)[source]

Wrapper allowing string arguments in a CLI fashion.

Parameters:

args (List[str]) – command line parameters as list of strings (for example ["--verbose", "42"]).

yourdfpy.viz.parse_args(args)[source]

Parse command line parameters

Parameters:

args (List[str]) – command line parameters as list of strings (for example ["--help"]).

Returns:

command line parameters namespace

Return type:

argparse.Namespace

yourdfpy.viz.run()[source]

Calls main() passing the CLI arguments extracted from sys.argv.

This function can be used as entry point to create console scripts with setuptools.

yourdfpy.viz.setup_logging(loglevel)[source]

Setup basic logging.

Parameters:

loglevel (int) – minimum loglevel for emitting messages

yourdfpy.viz.viewer_callback(scene, urdf_model, trajectory, loop_time)[source]

Module contents