Provides wrappers for performing KDL functions on a designated kinematic chain given a URDF representation of a robot. More...

Inheritance diagram for pykdl_utils.kdl_kinematics.KDLKinematics:

[legend]

List of all members.

Public Member Functions
def	__init__
	Constructor.
def	cart_inertia
	Returns the cartesian space mass matrix at the end_link for the given joint angles.
def	clip_joints_safe
	Clips joint angles to the safety limits.
def	difference_joints
	Returns a difference between the two sets of joint angles while insuring that the shortest angle is returned for the continuous joints.
def	extract_joint_state
def	FK
def	forward
	Forward kinematics on the given joint angles, returning the location of the end_link in the base_link's frame.
def	get_joint_limits
def	get_joint_names
def	get_link_names
def	inertia
	Returns the joint space mass matrix at the end_link for the given joint angles.
def	inverse
	Inverse kinematics for a given pose, returning the joint angles required to obtain the target pose.
def	inverse_biased
	Performs an IK search while trying to balance the demands of reaching the goal, maintaining a posture, and prioritizing rotation or position.
def	inverse_biased_search
	inverse_biased with random restarts.
def	inverse_search
	Repeats IK for different sets of random initial angles until a solution is found or the call times out.
def	jacobian
	Returns the Jacobian matrix at the end_link for the given joint angles.
def	joints_in_limits
	Tests to see if the given joint angles are in the joint limits.
def	joints_in_safe_limits
	Tests to see if the given joint angles are in the joint safety limits.
def	random_joint_angles
	Returns a set of random joint angles distributed uniformly in the safety limits.
Public Attributes
	base_link
	chain
	end_link
	joint_limits_lower
	joint_limits_upper
	joint_safety_lower
	joint_safety_upper
	joint_types
	num_joints
	tree
	urdf
Private Member Functions
def	_do_kdl_fk
Private Attributes
	_dyn_kdl
	_fk_kdl
	_ik_p_kdl
	_ik_v_kdl
	_jac_kdl

Detailed Description

Provides wrappers for performing KDL functions on a designated kinematic chain given a URDF representation of a robot.

Definition at line 56 of file kdl_kinematics.py.

Constructor & Destructor Documentation

def pykdl_utils.kdl_kinematics.KDLKinematics.__init__	(	self,
		urdf,
		base_link,
		end_link,
		kdl_tree = `None`
	)

Constructor.

Parameters:

urdf	URDF object of robot.
base_link	Name of the root link of the kinematic chain.
end_link	Name of the end link of the kinematic chain.
kdl_tree	Optional KDL.Tree object to use. If None, one will be generated from the URDF.

Reimplemented in pykdl_utils.joint_kinematics.JointKinematicsWait.

Definition at line 64 of file kdl_kinematics.py.

Member Function Documentation

def pykdl_utils.kdl_kinematics.KDLKinematics._do_kdl_fk	(	self,
		q,
		link_number
	)	`[private]`

Definition at line 202 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.cart_inertia	(	self,
		q
	)

Returns the cartesian space mass matrix at the end_link for the given joint angles.

Parameters:

q	List of joint angles.

Returns:: 6x6 np.mat Cartesian inertia matrix

Reimplemented in pykdl_utils.joint_kinematics.JointKinematicsBase.

Definition at line 302 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.clip_joints_safe	(	self,
		q
	)

Clips joint angles to the safety limits.

Parameters:

List	of joint angles.

Returns:: np.array list of clipped joint angles.

Definition at line 329 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.difference_joints	(	self,
		q1,
		q2
	)

Returns a difference between the two sets of joint angles while insuring that the shortest angle is returned for the continuous joints.

Parameters:

q1	List of joint angles.
q2	List of joint angles.

Returns:: np.array of wrapped joint angles for retval = q1 - q2

Definition at line 351 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.extract_joint_state	(	self,
		js,
		joint_names = `None`
	)

Definition at line 121 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.FK	(	self,
		q,
		link_number = `None`
	)

Definition at line 157 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.forward	(	self,
		q,
		end_link = `None`,
		base_link = `None`
	)

Forward kinematics on the given joint angles, returning the location of the end_link in the base_link's frame.

Parameters:

q	List of joint angles for the full kinematic chain.
end_link	Name of the link the pose should be obtained for.
base_link	Name of the root link frame the end_link should be found in.

Returns:: 4x4 numpy.mat homogeneous transformation

Reimplemented in pykdl_utils.joint_kinematics.JointKinematicsBase.

Definition at line 174 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.get_joint_limits ( self )

Definition at line 154 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.get_joint_names	(	self,
		links = `False`,
		fixed = `False`
	)

Returns:: List of joint names in the kinematic chain.

Definition at line 150 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.get_link_names	(	self,
		joints = `False`,
		fixed = `True`
	)

Returns:: List of link names in the kinematic chain.

Definition at line 145 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.inertia	(	self,
		q
	)

Returns the joint space mass matrix at the end_link for the given joint angles.

Parameters:

q	List of joint angles.

Returns:: NxN np.mat Inertia matrix

Reimplemented in pykdl_utils.joint_kinematics.JointKinematicsBase.

Definition at line 293 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.inverse	(	self,
		pose,
		q_guess = `None`,
		min_joints = `None`,
		max_joints = `None`
	)

Inverse kinematics for a given pose, returning the joint angles required to obtain the target pose.

Parameters:

pose	Pose-like object represeting the target pose of the end effector.
q_guess	List of joint angles to seed the IK search.
min_joints	List of joint angles to lower bound the angles on the IK search. If None, the safety limits are used.
max_joints	List of joint angles to upper bound the angles on the IK search. If None, the safety limits are used.

Returns:: np.array of joint angles needed to reach the pose or None if no solution was found.

Definition at line 227 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.inverse_biased	(	self,
		pose,
		q_init,
		q_bias,
		q_bias_weights,
		rot_weight = `1.`,
		bias_vel = `0.01`,
		num_iter = `100`
	)

Performs an IK search while trying to balance the demands of reaching the goal, maintaining a posture, and prioritizing rotation or position.

Definition at line 366 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.inverse_biased_search	(	self,
		pos,
		rot,
		q_bias,
		q_bias_weights,
		rot_weight = `1.`,
		bias_vel = `0.01`,
		num_iter = `100`,
		num_search = `20`
	)

inverse_biased with random restarts.

Definition at line 392 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.inverse_search	(	self,
		pose,
		timeout = `1.`
	)

Repeats IK for different sets of random initial angles until a solution is found or the call times out.

Parameters:

pose	Pose-like object represeting the target pose of the end effector.
timeout	Time in seconds to look for a solution.

Returns:: np.array of joint angles needed to reach the pose or None if no solution was found.

Definition at line 263 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.jacobian	(	self,
		q,
		pos = `None`
	)

Returns the Jacobian matrix at the end_link for the given joint angles.

Parameters:

q	List of joint angles.

Returns:: 6xN np.mat Jacobian

Parameters:

pos	Point in base frame where the jacobian is acting on. If None, we assume the end_link

Definition at line 278 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.joints_in_limits	(	self,
		q
	)

Tests to see if the given joint angles are in the joint limits.

Parameters:

List	of joint angles.

Returns:: True if joint angles in joint limits.

Definition at line 311 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.joints_in_safe_limits	(	self,
		q
	)

Tests to see if the given joint angles are in the joint safety limits.

Parameters:

List	of joint angles.

Returns:: True if joint angles in joint safety limits.

Definition at line 320 of file kdl_kinematics.py.

def pykdl_utils.kdl_kinematics.KDLKinematics.random_joint_angles ( self )

Returns a set of random joint angles distributed uniformly in the safety limits.

Returns:: np.array list of random joint angles.

Definition at line 337 of file kdl_kinematics.py.

Member Data Documentation

pykdl_utils::kdl_kinematics.KDLKinematics::_dyn_kdl [private]

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::_fk_kdl [private]

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::_ik_p_kdl [private]

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::_ik_v_kdl [private]

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::_jac_kdl [private]

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::base_link

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::chain

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::end_link

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::joint_limits_lower

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::joint_limits_upper

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::joint_safety_lower

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::joint_safety_upper

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::joint_types

Reimplemented in pykdl_utils.joint_kinematics.JointKinematicsBase.

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::num_joints

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::tree

Definition at line 64 of file kdl_kinematics.py.

pykdl_utils::kdl_kinematics.KDLKinematics::urdf

Definition at line 64 of file kdl_kinematics.py.

The documentation for this class was generated from the following file:

kdl_kinematics.py

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation