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OSCAR::IKJTranspose Class Reference
[InverseKinematics]

This class contains methods for calculating inverse position solutions for serial manipulators (especially low DOF manipulators) using the Jacobian Transpose technique. More...

#include <IKJTranspose.h>

Inheritance diagram for OSCAR::IKJTranspose:

[legend]List of all members.


Public Methods
	IKJTranspose (JointVector &initialJointPosition, FKJacobian *fkJacobian, double errorBound=0.1)
	IKJTranspose (const IKJTranspose &rhs)
IKJTranspose &	operator= (const IKJTranspose &rhs)
virtual	~IKJTranspose ()
bool	GetJointPosition (const HandPose &desiredHand, JointVector &jointPosition)
bool	GetJointPosition (const Xform &desiredHand, JointVector &jointPosition)
bool	SetWeightMatrix (Matrix &weights)
bool	SetErrorBound (double &errorBound)
bool	SetMaxIterations (int &iterations)
Protected Methods
double	calculateErrorMagnitude (const HandPose &desiredHand, const HandPose &currentHand, HandPose &error_hand)
Protected Attributes
FKJacobian *	fkJDummy
unsigned int	dof
Matrix	currentJacobian
Matrix	currentJacobianTranspose
Vector	currentJoints
Vector	jtTimesE
HandPose	xdMinusXc
Vector	weightedXdXc
Matrix	weightMatrix
unsigned int	maxIterations
unsigned int	iterations
double	errorbound

Detailed Description

Author:: Jeremy Sevier & Peter S. March

Constructor & Destructor Documentation

OSCAR::IKJTranspose::IKJTranspose ( JointVector & initialJointPosition,

FKJacobian * fkJacobian,

double errorBound = 0.1

)

Constructor.
This is the constructor for an object of type IKJTranspose. Use this Constructor to create an IKJTranspose object from an FKJacobian object and an initial joint position. This class uses the Jacobian calculations from the FKJacobian class to perform a Jacobian Transpose inverse solution. As such, all functionality for setting and retrieving tool points and base poses should be done through the FKJacobian object.
Parameters:

initialJointPosition A DOF length vector of initial joint positions. This position will be used to create the object and should not be singular.

fkJacobian A pointer to an FKJacobian class. This object will be used to generate the Jacobian used for the inverse. All necessary tool points and base poses should be set in this object. A user can supply their custom FKJacobian object for this purpose.

errorBound is used as the maximum error allowed for the solution its default is 0.1

OSCAR::IKJTranspose::IKJTranspose ( const IKJTranspose & rhs )

Copy Constructor.
This is the Copy constructor for an object of type IKJTranspose. Use this to construct an IKJTranspose based on an existing IKJacobian object.
Parameters:

rhs An IKJTranspose object that will be used to initialize this new object.

virtual OSCAR::IKJTranspose::~IKJTranspose ( ) [virtual]

Virtual Destructor.
This is the Destructor for an IKJacobian object.

Member Function Documentation

double OSCAR::IKJTranspose::calculateErrorMagnitude ( const HandPose & desiredHand,

const HandPose & currentHand,

HandPose & error_hand

) [protected]

bool OSCAR::IKJTranspose::GetJointPosition ( const Xform & desiredHand,

JointVector & jointPosition

)

Get the Joint position.
This method is used to get the current joint position solution for an end-effector position represented by an Xform object.
Parameters:

desiredHand A transform matrix representing the desired end-effector position.

jointPosition A DOF long vector (where DOF is the number of joints or degrees of freedom).

Returns:
True if the method succeeds. Otherwise False. Call GetError() to get detailed error information.

See also:
GetJointPosition(const HandPose& desiredHand, JointVector& jointPosition)

bool OSCAR::IKJTranspose::GetJointPosition ( const HandPose & desiredHand,

JointVector & jointPosition

)

Get the Joint position.
This method is used to get the current joint position solution for an end-effector position represented by an HandPose object.
Parameters:

desiredHand. A 6 DOF vector representing the desired end-effector position & orientation.

jointPosition A DOF long vector (where DOF is the number of joints or degrees of freedom).

Returns:
True if the method succeeds. Otherwise False. Call GetError() to get detailed error information.

See also:
GetJointPosition(const Xform& desiredHand, JointVector& jointPosition)

IKJTranspose& OSCAR::IKJTranspose::operator= ( const IKJTranspose & rhs )

Assignment operator.
This is the Assignment operator for an object of type IKJTranspose.
Parameters:

rhs An IKJTranspose object that goes on the right hand side of the = operator.

Returns:
A reference to the object on the left hand side of the = operator.

bool OSCAR::IKJTranspose::SetErrorBound ( double & errorBound )

Set the Error Bound.
This method Sets the maximum error for a solution to be considered solved. It measures the norm of the weighted difference between the desired and current hand positions, and if the current hand is less than the error bound, it considers the current hand a solution to the Inverse Kinematics problem.
Parameters:

errorBound is a double specifying the maximum error for the IK solution.

bool OSCAR::IKJTranspose::SetMaxIterations ( int & iterations )

Maximum number of iterations.
This method Sets the number of iterations for a solution.

Parameters:

iterations is a double specifying the maximum number of iterations before IKJTranspose returns a solution.

bool OSCAR::IKJTranspose::SetWeightMatrix ( Matrix & weights )

Set the Weight Matrix.
This method Sets the importance of a desired DOF. It defaults as an Identity matrix, but if say you just care about the position, you could use the first three diagonal elements (position) as 1's and the last three (orientation) as 0's.

Parameters:

weights is a 6x6 matrix of weights corresponding to the coordinate space.