ikpy.chain module¶

class ikpy.chain.Chain(links, active_links=0, profile='', **kwargs)[source]¶

Bases: object

The base Chain class

Parameters:	links (list) – List of the links of the chain active_links (list) – The list of the positions of the active links

forward_kinematics(joints, full_kinematics=False)[source]¶

Returns the transformation matrix of the forward kinematics

Parameters:	joints (list) – The list of the positions of each joint. Note : Inactive joints must be in the list. full_kinematics (bool) – Return the transorfmation matrixes of each joint
Returns:	The transformation matrix

inverse_kinematic(target, initial_position, first_active_joint=0, **kwargs)[source]¶

Computes the inverse kinematic on the specified target

Parameters:	target (numpy.array) – The target of the inverse kinematic, in meters initial_position (numpy.array) – the initial position of each joint of the chain first_active_joint (int) – The first active joint$
Returns:	The list of the positions of each joint according to the target. Note : Inactive joints are in the list.

plot(joints, ax, target=None, show=False)[source]¶

Plots the Chain using Matplotlib

Parameters:	joints (list) – The list of the positions of each joint ax (matplotlib.axes.Axes) – A matplotlib axes target (numpy.array) – An optional target show (bool) – Display the axe. Defaults to False

classmethod from_urdf_file(urdf_file, base_elements=['base_link'], last_link_vector=None, base_elements_type='joint')[source]¶

Creates a chain from an URDF file

Parameters:	urdf_file (string) – The path of the URDF file base_elements (list of strings) – List of the links beginning the chain last_link_vector (numpy.array) – Optional : The translation vector of the tip.

ikpy.chain.pinv()[source]¶

ikpy.link module¶

class ikpy.link.Link(name, bounds=(None, None))[source]¶

Bases: object

Base Link class.

Parameters:	name (string) – The name of the link bounds (tuple) – Optional : The bounds of the link. Defaults to None use_symbolic_matrix (bool) – wether the transformation matrix is stored as Numpy array or as a Sympy symbolic matrix.

get_transformation_matrix(theta)[source]¶

class ikpy.link.URDFLink(name, translation_vector, orientation, rotation, bounds=(None, None), angle_representation='rpy', use_symbolic_matrix=False)[source]¶

Bases: ikpy.link.Link

Link in URDF representation.

Parameters:	name (string) – The name of the link bounds (tuple) – Optional : The bounds of the link. Defaults to None translation_vector (numpy.array) – The translation vector. (In URDF, attribute “xyz” of the “origin” element) orientation (numpy.array) – The orientation of the link. (In URDF, attribute “rpy” of the “origin” element) rotation (numpy.array) – The rotation axis of the link. (In URDF, attribute “xyz” of the “axis” element) angle_representation (string) – Optionnal : The representation used by the angle. Currently supported representations : rpy. Defaults to rpy, the URDF standard. use_symbolic_matrix (bool) – wether the transformation matrix is stored as a Numpy array or as a Sympy symbolic matrix.
Returns:	The link object
Return type:	URDFLink
Example:

URDFlink()

get_transformation_matrix(theta)[source]¶

class ikpy.link.DHLink(name, d=0, a=0, bounds=None, use_symbolic_matrix=True)[source]¶

Bases: ikpy.link.Link

Link in Denavit-Hartenberg representation.

Parameters:	name (string) – The name of the link bounds (tuple) – Optional : The bounds of the link. Defaults to None d (float) – offset along previous z to the common normal a (float) – offset along previous to the common normal use_symbolic_matrix (bool) – wether the transformation matrix is stored as Numpy array or as a Sympy symbolic matrix.
Returns:	The link object
Return type:	DHLink

get_transformation_matrix(theta, a)[source]¶

Computes the homogeneous transformation matrix for this link.

class ikpy.link.OriginLink[source]¶

Bases: ikpy.link.Link

The link at the origin of the robot

get_transformation_matrix(theta)[source]¶

ikpy.inverse_kinematics module¶

ikpy.inverse_kinematics.inverse_kinematic_optimization(chain, target, starting_nodes_angles, bounds=None, first_active_joint=0, regularization_parameter=None, max_iter=None, **kwargs)[source]¶

Computes the inverse kinematic on the specified target with an optimization method

ikpy.geometry_utils module¶

ikpy.geometry_utils.Rx_matrix(theta)[source]¶

Rotation matrix around the X axis

ikpy.geometry_utils.Rz_matrix(theta)[source]¶

Rotation matrix around the Z axis

ikpy.geometry_utils.symbolic_Rz_matrix(symbolic_theta)[source]¶

Matrice symbolique de rotation autour de l’axe Z

ikpy.geometry_utils.Ry_matrix(theta)[source]¶

Rotation matrix around the Y axis

ikpy.geometry_utils.rotation_matrix(phi, theta, psi)[source]¶

Retourne la matrice de rotation décrite par les angles d’Euler donnés en paramètres

ikpy.geometry_utils.symbolic_rotation_matrix(phi, theta, symbolic_psi)[source]¶

Retourne une matrice de rotation où psi est symbolique

ikpy.geometry_utils.rpy_matrix(roll, pitch, yaw)[source]¶

Returns a rotation matrix described by the extrinsinc roll, pitch, yaw coordinates

ikpy.geometry_utils.axis_rotation_matrix(axis, theta)[source]¶

Returns a rotation matrix around the given axis

ikpy.geometry_utils.symbolic_axis_rotation_matrix(axis, symbolic_theta)[source]¶

Returns a rotation matrix around the given axis

ikpy.geometry_utils.homogeneous_translation_matrix(trans_x, trans_y, trans_z)[source]¶

Returns a translation matrix the homogeneous space

ikpy.geometry_utils.from_transformation_matrix(transformation_matrix)[source]¶

Converts a transformation matrix to a tuple (rotation_matrix, translation_vector)

ikpy.geometry_utils.to_transformation_matrix(rotation_matrix, translation)[source]¶

Converts a tuple (rotation_matrix, translation_vector) to a transformation matrix

ikpy.geometry_utils.cartesian_to_homogeneous(cartesian_matrix, matrix_type='numpy')[source]¶

Converts a cartesian matrix to an homogenous matrix

ikpy.geometry_utils.cartesian_to_homogeneous_vectors(cartesian_vector, matrix_type='numpy')[source]¶

Converts a cartesian vector to an homogenous vector

ikpy.geometry_utils.homogeneous_to_cartesian_vectors(homogeneous_vector)[source]¶

Converts a cartesian vector to an homogenous vector

ikpy.geometry_utils.homogeneous_to_cartesian(homogeneous_matrix)[source]¶

Converts a cartesian vector to an homogenous matrix

ikpy.URDF_utils module¶

ikpy.URDF_utils.find_next_joint(root, current_link, next_joints)[source]¶

Find the next joint in the URDF tree

ikpy.URDF_utils.find_next_link(root, current_joint, next_links)[source]¶

Find the next link in the URDF tree

ikpy.URDF_utils.find_parent_link(root, joint_name)[source]¶

ikpy.URDF_utils.get_chain_from_joints(urdf_file, joints)[source]¶

ikpy.URDF_utils.get_urdf_parameters(urdf_file, base_elements=['base_link'], last_link_vector=None, base_elements_type='joint')[source]¶

Returns translated parameters from the given URDF file

Parameters:	urdf_file (string) – The path of the URDF file base_elements (list of strings) – List of the links beginning the chain last_link_vector (numpy.array) – Optional : The translation vector of the tip.

ikpy.URDF_utils.get_motor_parameters(json_file)[source]¶

Returns a dictionnary with joints as keys, and a description (dict) of each joint as value

ikpy.URDF_utils.convert_angle_to_pypot(angle, joint, **kwargs)[source]¶

Converts an angle to a PyPot-compatible format

ikpy.URDF_utils.convert_angle_from_pypot(angle, joint, **kwargs)[source]¶

Converts an angle to a PyPot-compatible format

ikpy.URDF_utils.convert_angle_limit(angle, joint, **kwargs)[source]¶

Converts the limit angle of the PyPot JSON file to the internal format