Parsers

Parsers#

class jaxsim.parsers.descriptions.collision.BoxCollision(collidable_points, center)[source]#

Represents a box-shaped collision shape.

Parameters:

collidable_points (tuple[CollidablePoint])
center (tuple[float, float, float])

center#: The center of the box in the local frame of the collision shape.

class jaxsim.parsers.descriptions.collision.CollidablePoint(parent_link, enabled=True, _position=(0.0, 0.0, 0.0))[source]#

Represents a collidable point associated with a parent link.

Parameters:

parent_link (LinkDescription)
enabled (bool)
_position (tuple[float])

parent_link#: The parent link to which the collidable point is attached.

position#: The position of the collidable point relative to the parent link.

enabled#: A flag indicating whether the collidable point is enabled for collision detection.

change_link(new_link, new_H_old)[source]#

Move the collidable point to a new parent link.

Parameters:

new_link (LinkDescription) – The new parent link to which the collidable point is moved.
new_H_old (ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]) – The transformation matrix from the new link’s frame to the old link’s frame.

Returns:

A new collidable point associated with the new parent link.

Return type:

CollidablePoint

property position: ndarray[tuple[int, ...], dtype[_ScalarType_co]]#

Get the position of the collidable point.

Returns:: The position of the collidable point.

class jaxsim.parsers.descriptions.collision.CollisionShape(collidable_points)[source]#

Abstract base class for representing collision shapes.

Parameters:: collidable_points (tuple[CollidablePoint])

collidable_points#: A list of collidable points associated with the collision shape.

class jaxsim.parsers.descriptions.collision.MeshCollision(collidable_points, center)[source]#

Represents a mesh-shaped collision shape.

Parameters:

collidable_points (tuple[CollidablePoint])
center (tuple[float, float, float])

center#: The center of the mesh in the local frame of the collision shape.

class jaxsim.parsers.descriptions.collision.SphereCollision(collidable_points, center)[source]#

Represents a spherical collision shape.

Parameters:

collidable_points (tuple[CollidablePoint])
center (tuple[float, float, float])

center#: The center of the sphere in the local frame of the collision shape.

class jaxsim.parsers.descriptions.joint.JointDescription(name, _axis, _pose, jtype, child=<factory>, parent=<factory>, index=None, friction_static=0.0, friction_viscous=0.0, position_limit_damper=0.0, position_limit_spring=0.0, position_limit=(0.0, 0.0), _initial_position=0.0, motor_inertia=0.0, motor_viscous_friction=0.0, motor_gear_ratio=1.0)[source]#

In-memory description of a robot joint.

Parameters:

name (str)
_axis (tuple[float])
_pose (tuple[float])
jtype (int)
child (LinkDescription)
parent (LinkDescription)
index (int | None)
friction_static (float)
friction_viscous (float)
position_limit_damper (float)
position_limit_spring (float)
position_limit (tuple[float, float])
_initial_position (float | tuple[float])
motor_inertia (float)
motor_viscous_friction (float)
motor_gear_ratio (float)

name#: The name of the joint.

axis#: The axis of rotation or translation for the joint.

pose#: The pose transformation matrix of the joint.

jtype#: The type of the joint.

child#: The child link attached to the joint.

parent#: The parent link attached to the joint.

index#: An optional index for the joint.

friction_static#: The static friction coefficient for the joint.

friction_viscous#: The viscous friction coefficient for the joint.

position_limit_damper#: The damper coefficient for position limits.

position_limit_spring#: The spring coefficient for position limits.

position_limit#: The position limits for the joint.

initial_position#: The initial position of the joint.

property axis: ndarray[tuple[int, ...], dtype[_ScalarType_co]]#

Get the axis of the joint.

Returns:: The axis of the joint.
Return type:: npt.NDArray

property initial_position: float | ndarray[tuple[int, ...], dtype[_ScalarType_co]]#

Get the initial position of the joint.

Returns:: The initial position of the joint.

property pose: ndarray[tuple[int, ...], dtype[_ScalarType_co]]#

Get the pose of the joint.

Returns:: The pose of the joint.

class jaxsim.parsers.descriptions.joint.JointType[source]#

Enumeration of joint types.

class jaxsim.parsers.descriptions.link.LinkDescription(name, mass, _inertia, index=None, parent_name=None, _pose=([1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], [0.0, 0.0, 0.0, 1.0]), children=<factory>)[source]#

In-memory description of a robot link.

Parameters:

name (str)
mass (float)
_inertia (tuple[float])
index (int | None)
parent_name (str | None)
_pose (tuple[float])
children (tuple[LinkDescription])

name#: The name of the link.

mass#: The mass of the link.

inertia#: The inertia tensor of the link.

index#: An optional index for the link (it gets automatically assigned).

parent#: The parent link of this link.

pose#: The pose transformation matrix of the link.

children#: The children links.

property inertia: ndarray[tuple[int, ...], dtype[_ScalarType_co]]#

Get the inertia tensor of the link.

Returns:: The inertia tensor of the link.
Return type:: npt.NDArray

lump_with(link, lumped_H_removed)[source]#

Combine the current link with another link, preserving mass and inertia.

Parameters:

link (LinkDescription) – The link to combine with.
lumped_H_removed (Array) – The transformation matrix between the two links.

Return type:

LinkDescription

Returns:

The combined link.

property name_and_index: str#

Get a formatted string with the link’s name and index.

Returns:: The formatted string.
Return type:: str

property pose: ndarray[tuple[int, ...], dtype[_ScalarType_co]]#

Get the pose transformation matrix of the link.

Returns:: The pose transformation matrix of the link.
Return type:: npt.NDArray

class jaxsim.parsers.descriptions.model.ModelDescription(root, frames=<factory>, joints=<factory>, root_pose=<factory>, _extra_info=<factory>, _joints_removed=<factory>, name=None, fixed_base=True, collision_shapes=<factory>)[source]#

Intermediate representation representing the kinematic graph of a robot model.

Parameters:

root (LinkDescription)
frames (list[LinkDescription])
joints (list[JointDescription])
root_pose (RootPose)
_extra_info (dict[str, Any])
_joints_removed (list[JointDescription])
name (str)
fixed_base (bool)
collision_shapes (tuple[CollisionShape, ...])

name#: The name of the model.

fixed_base#: Whether the model is either fixed-base or floating-base.

collision_shapes#: List of collision shapes associated with the model.

all_enabled_collidable_points()[source]#

Get all enabled collidable points in the model.

Return type:: list[CollidablePoint]
Returns:: The list of all enabled collidable points.

static build_model_from(name, links, joints, frames=None, collisions=(), fixed_base=False, base_link_name=None, considered_joints=None, model_pose=RootPose(_root_position=(0.0, 0.0, 0.0), _root_quaternion=(1.0, 0.0, 0.0, 0.0)))[source]#

Build a model description from provided components.

Parameters:

name (str) – The name of the model.
links (list[LinkDescription]) – List of link descriptions.
joints (list[JointDescription]) – List of joint descriptions.
frames (list[LinkDescription] | None) – List of frame descriptions.
collisions (tuple[CollisionShape, ...]) – List of collision shapes associated with the model.
fixed_base (bool) – Indicates whether the model has a fixed base.
base_link_name (str | None) – Name of the base link (i.e. the root of the kinematic tree).
considered_joints (Sequence[str] | None) – List of joint names to consider (by default all joints).
model_pose (RootPose) – Pose of the model’s root (by default an identity transform).

Return type:

ModelDescription

Returns:

A ModelDescription instance representing the model.

collision_shape_of_link(link_name)[source]#

Get the collision shape associated with a specific link.

Parameters:: link_name (str) – The name of the link.
Return type:: CollisionShape
Returns:: The collision shape associated with the link.

reduce(considered_joints)[source]#

Reduce the model by removing specified joints.

Parameters:: considered_joints (Sequence[str]) – Sequence of joint names to consider.
Return type:: ModelDescription
Returns:: A ModelDescription instance that only includes the considered joints.

update_collision_shape_of_link(link_name, enabled)[source]#

Enable or disable collision shapes associated with a link.

Parameters:

link_name (str) – The name of the link.
enabled (bool) – Enable or disable collision shapes associated with the link.

Return type:

None

Parsers

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Parsers#