Package org.robwork.sdurw

Class PieperSolver

java.lang.Object

org.robwork.sdurw.InvKinSolver

org.robwork.sdurw.ClosedFormIK

org.robwork.sdurw.PieperSolver

public class PieperSolver
extends ClosedFormIK

Calculates the closed form inverse kinematics of
a device using Piepers method

To use Piepers method it is required that the device has
6 DOF revolute joints, and that last three axis intersects.
In this implementation it will be assumed that the that
rotation of these last three axis are equivalent to an
Euler ZYZ or Z(-Y)Z rotation.

See Introduction to Robotics Mechanics and Control, by
John J. Craig for further information about the algorithm.

Constructor Summary

Constructors

Constructor	Description
PieperSolver(long cPtr, boolean cMemoryOwn)
PieperSolver(DHParameterSetVector dhparams, Transform3Dd joint6Tend)	Constructor
PieperSolver(DHParameterSetVector dhparams, Transform3Dd joint6Tend, Transform3Dd baseTdhRef)	Constructor
PieperSolver(SerialDevice dev, Transform3Dd joint6Tend, State state)	Constructor - the DH parameters is expected to be on each joint in the serial device.

Method Summary

Modifier and Type	Method	Description
void	delete()
static long	getCPtr(PieperSolver obj)
FrameCPtr	getTCP()	Returns the Tool Center Point (TCP) used when solving the IK problem.
void	setCheckJointLimits(boolean check)	Specifies whether to check joint limits before returning a solution.
VectorQ	solve(Transform3Dd baseTend, State state)	Calculates the inverse kinematics Given a desired transformation and the current state, the method solves the inverse kinematics problem.

Methods inherited from class org.robwork.sdurw.ClosedFormIK

getCPtr, make

Methods inherited from class org.robwork.sdurw.InvKinSolver

getCPtr

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PieperSolver

public PieperSolver(long cPtr,
                    boolean cMemoryOwn)

PieperSolver

public PieperSolver(DHParameterSetVector dhparams,
                    Transform3Dd joint6Tend,
                    Transform3Dd baseTdhRef)

Constructor

Parameters:

dhparams - [in] DH-parameters corresponding to the device

joint6Tend - [in] transform from the 6th joint to the end of the device

baseTdhRef - [in] Transformation between the robot base and the reference frame for the DH-parameters.

PieperSolver

public PieperSolver(DHParameterSetVector dhparams,
                    Transform3Dd joint6Tend)

Constructor

Parameters:

dhparams - [in] DH-parameters corresponding to the device

joint6Tend - [in] transform from the 6th joint to the end of the device

PieperSolver

public PieperSolver(SerialDevice dev,
                    Transform3Dd joint6Tend,
                    State state)

Constructor - the DH parameters is expected to be on each joint
in the serial device. When specifying the DH params in the workcell file
this constructor can be used.

Parameters:

dev - [in] the device for which to extract the DH parameters.

joint6Tend - [in] transform from the 6th joint to the end of the device

state - [in] State using which the transformation between robot base and the DH-parameters reference frame are calculated.

Note: throws an exception if the device has no DH params

Method Detail

getCPtr

public static long getCPtr(PieperSolver obj)

delete

public void delete()

Overrides:

delete in class ClosedFormIK

solve

public VectorQ solve(Transform3Dd baseTend,
                     State state)

Calculates the inverse kinematics

Given a desired transformation
and the current state, the method solves the inverse kinematics
problem.

If the algorithm is able to identify multiple solutions (e.g. elbow
up and down) it will return all of these. Before returning a solution,
they may be checked to be within the bounds of the configuration space.
(See setCheckJointLimits(bool) )

Overrides:

solve in class InvKinSolver

Parameters:

baseTend - [in] Desired base to end transformation.

state - [in] State of the device from which to start the
iterations

Returns:

List of solutions. Notice that the list may be empty.

Note: The targets baseTend must be defined relative to the base of the
robot/device.

setCheckJointLimits

public void setCheckJointLimits(boolean check)

Specifies whether to check joint limits before returning a solution.

Overrides:

setCheckJointLimits in class InvKinSolver

Parameters:

check - [in] If true the method should perform a check that joints are within bounds.

getTCP

public FrameCPtr getTCP()

Returns the Tool Center Point (TCP) used when solving the IK problem.

Overrides:

getTCP in class InvKinSolver

Returns:

The TCP Frame used when solving the IK.