pykdl_utils.joint_kinematics.JointKinematics Class Reference

Kinematics class which subscribes to the /joint_states topic, recording the current joint states for the kinematic chain designated. More...

Inheritance diagram for pykdl_utils.joint_kinematics.JointKinematics:

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	end_effector_force
	Returns the current effective end effector force.
def	forward
	Perform forward kinematics on the current joint angles.
def	get_joint_angles
	Returns the current joint angle positions.
def	get_joint_efforts
	Returns the current joint efforts.
def	get_joint_velocities
	Returns the current joint velocities.
def	inertia
	Returns the joint space mass matrix at the end_link for the given joint angles.
def	jacobian
	Returns the Jacobian matrix at the end_link from the current joint angles.
def	wait_for_joint_angles
	Wait until we have found the current joint angles.
def	wrap_angles
	Returns joint angles for continuous joints to a range [0, 2*PI)
Public Attributes
	joint_types
Private Member Functions
def	_joint_state_cb
	Joint angles listener callback.
Private Attributes
	_joint_angles
	_joint_efforts
	_joint_state_inds
	_joint_velocities

---

Detailed Description

Kinematics class which subscribes to the /joint_states topic, recording the current joint states for the kinematic chain designated.

Definition at line 54 of file joint_kinematics.py.

---

Constructor & Destructor Documentation

def pykdl_utils.joint_kinematics.JointKinematics.__init__	(		self,
			urdf,
			base_link,
			end_link,
			kdl_tree = None,
			timeout = 1.
	)

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.
timeout	Time in seconds to wait for the /joint_states topic.

Definition at line 63 of file joint_kinematics.py.

---

Member Function Documentation

def pykdl_utils.joint_kinematics.JointKinematics._joint_state_cb	(		self,
			msg
	)		[private]

Joint angles listener callback.

Definition at line 77 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.cart_inertia	(		self,
			q = None
	)

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 or None if the joint angles are not filled.

Reimplemented from pykdl_utils.kdl_kinematics.KDLKinematics.

Definition at line 174 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.end_effector_force

(

self

)

Returns the current effective end effector force.

Definition at line 191 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.forward	(		self,
			q = None,
			end_link = None,
			base_link = None
	)

Perform forward kinematics on the current joint angles.

Parameters:

q	List of joint angles for the full kinematic chain. If None, the current joint angles are used.
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 or None if the joint angles are not filled.

Reimplemented from pykdl_utils.kdl_kinematics.KDLKinematics.

Definition at line 141 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.get_joint_angles	(		self,
			wrapped = False
	)

Returns the current joint angle positions.

Parameters:

wrapped

If False returns the raw encoded positions, if True returns the angles with the forearm and wrist roll in the range -pi to pi

Definition at line 109 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.get_joint_efforts

(

self

)

Returns the current joint efforts.

Definition at line 128 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.get_joint_velocities

(

self

)

Returns the current joint velocities.

Definition at line 120 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.inertia	(		self,
			q = None
	)

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 or None if the joint angles are not filled.

Reimplemented from pykdl_utils.kdl_kinematics.KDLKinematics.

Definition at line 163 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.jacobian	(		self,
			q = None
	)

Returns the Jacobian matrix at the end_link from the current joint angles.

Parameters:

q	List of joint angles. If None, the current joint angles are used.

Returns:

6xN np.mat Jacobian or None if the joint angles are not filled.

Definition at line 152 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.wait_for_joint_angles	(		self,
			timeout = 1.
	)

Wait until we have found the current joint angles.

Parameters:

timeout

Time at which we break if we haven't recieved the angles.

Definition at line 92 of file joint_kinematics.py.

def pykdl_utils.joint_kinematics.JointKinematics.wrap_angles	(		self,
			q
	)

Returns joint angles for continuous joints to a range [0, 2*PI)

Parameters:

q	List of joint angles.

Returns:

np.array of wrapped joint angles.

Definition at line 185 of file joint_kinematics.py.

---

Member Data Documentation

pykdl_utils::joint_kinematics.JointKinematics::_joint_angles [private]

Definition at line 63 of file joint_kinematics.py.

pykdl_utils::joint_kinematics.JointKinematics::_joint_efforts [private]

Definition at line 63 of file joint_kinematics.py.

pykdl_utils::joint_kinematics.JointKinematics::_joint_state_inds [private]

Definition at line 63 of file joint_kinematics.py.

pykdl_utils::joint_kinematics.JointKinematics::_joint_velocities [private]

Definition at line 63 of file joint_kinematics.py.

pykdl_utils::joint_kinematics.JointKinematics::joint_types

Reimplemented from pykdl_utils.kdl_kinematics.KDLKinematics.

Definition at line 185 of file joint_kinematics.py.

---

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

• joint_kinematics.py