javax.robotics.engine.clik
Class ClikJacobianPosInverse

java.lang.Object
  javax.robotics.engine.clik.ClikJacobianPosInverse

All Implemented Interfaces:

CLIKR

Direct Known Subclasses:

ClikJacobianPosTranspose

public class ClikJacobianPosInverse
extends java.lang.Object
implements CLIKR

Closed Loop Inverse Kinematics with positional Jacobian inverse. The class implements the same scheme depicted in ClikJacobianInverse:
The inverse is computed using SVD decomposition:

J^-1 = J^T*(J*J^T + λ²*I)^-1
where λ² is the damped factor equals 1 - (σ_r/ε)*λ²_max if σ_r< ε, equals 0 if σ_r≥ ε; σ_r is the smallest not null singular value.

The orientation error is not computed.
The integration method used is the forward Euler.

Since:

1.0.2

Version:

11/11/2005

Author:

Carmine Lia

See Also:

the solution without velocity constraint., the solution with velocity constraint.

Constructor Summary

ClikJacobianPosInverse(Robot robot, DMatrix Kp)
Costructor with default sample time, dt = 1e-3 and eps = 0.02, lambdaMax=0.02, the space dimension = 3.

ClikJacobianPosInverse(Robot robot, DMatrix Kp, double dt, int spaceDim, double eps, double lambdaMax)
Constructor.

ClikJacobianPosInverse(Robot robot, DMatrix Kp, int spaceDim)
Costructor with default sample time, dt = 1e-3 and eps = 0.02, lambdaMax=0.02.

ClikJacobianPosInverse(Robot robot, DMatrix Kp, int spaceDim, double dt)
Costructor with eps = 0.02, lambdaMax=0.02.

Method Summary

int	getCartesianSpaceDim() Gets the dimension of cartesian space.
double	getEps() Gets the singular region area.
RVector	getJointsPosition() Gets the current joints position.
RVector	getJointsVelocity() Gets the current joints velocity.
DMatrix	getKp() Gets the matrix of error position gain.
double	getLambdaMax() Gets the maximum damped factor.
RVector3d	getPositionError() Gets the current position error.
double	getSampleTime() Gets the sample time.
void	setEps(double eps) Sets the singular region area.
void	setKp(DMatrix kp) Sets the matrix of error position gain.
void	setLambdaMax(double lambdaMax) Sets the maximum damped factor.
void	setSampleTime(double h) Sets the sample time.
void	step(RVector pd, RVector ppd) Compute the joints position and velocity from a given desired end effector position and velocity.
void	step(RVector pd, RVector ppd, ConstraintVelocity constraint) Compute the joints position and velocity from a given desired end effector position and velocity with velocity constraint.

Methods inherited from class java.lang.Object

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

Constructor Detail

ClikJacobianPosInverse

public ClikJacobianPosInverse(Robot robot,
                              DMatrix Kp)

Costructor with default sample time, dt = 1e-3 and eps = 0.02, lambdaMax=0.02, the space dimension = 3.

Parameters:

robot - the robot.

Kp - the diagonal matrix of error position gain.

ClikJacobianPosInverse

public ClikJacobianPosInverse(Robot robot,
                              DMatrix Kp,
                              int spaceDim)

Costructor with default sample time, dt = 1e-3 and eps = 0.02, lambdaMax=0.02.

Parameters:

robot - the robot.

Kp - the diagonal matrix of error position gain.

spaceDim - the dimension of robot operational space.

ClikJacobianPosInverse

public ClikJacobianPosInverse(Robot robot,
                              DMatrix Kp,
                              int spaceDim,
                              double dt)

Costructor with eps = 0.02, lambdaMax=0.02.

Parameters:

robot - the robot.

Kp - the diagonal matrix of error position gain.

spaceDim - the dimension of robot operational space.

dt - the sample time.

ClikJacobianPosInverse

public ClikJacobianPosInverse(Robot robot,
                              DMatrix Kp,
                              double dt,
                              int spaceDim,
                              double eps,
                              double lambdaMax)

Constructor.

Parameters:

robot - the robot.

Kp - the diagonal matrix of error position gain.

spaceDim - the dimension of robot operational space.

dt - the sample time.

eps - the area of singular region.

lambdaMax - the maximum of damped factor.

Method Detail

getCartesianSpaceDim

public final int getCartesianSpaceDim()

Description copied from interface: CLIKR

Gets the dimension of cartesian space. For planar robots the value is 2, the value is set from dimension of diagonal matrix gain Kp.

Specified by:

getCartesianSpaceDim in interface CLIKR

Returns:

the dimension value.

getEps

public final double getEps()

Description copied from interface: CLIKR

Gets the singular region area.

Specified by:

getEps in interface CLIKR

Returns:

the eps.

setEps

public final void setEps(double eps)

Description copied from interface: CLIKR

Sets the singular region area.

Specified by:

setEps in interface CLIKR

Parameters:

eps - The eps to set.

getSampleTime

public final double getSampleTime()

Description copied from interface: CLIKR

Gets the sample time.

Specified by:

getSampleTime in interface CLIKR

Returns:

the sample time.

setSampleTime

public final void setSampleTime(double h)

Description copied from interface: CLIKR

Sets the sample time.

Specified by:

setSampleTime in interface CLIKR

Parameters:

h - The sample time to set.

getKp

public final DMatrix getKp()

Description copied from interface: CLIKR

Gets the matrix of error position gain.

Specified by:

getKp in interface CLIKR

Returns:

the diagonal matrix.

setKp

public final void setKp(DMatrix kp)

Description copied from interface: CLIKR

Sets the matrix of error position gain. The matrix must be of dimension 2 for planar robots.

Specified by:

setKp in interface CLIKR

Parameters:

kp - The diagonal matrix to set.

getLambdaMax

public final double getLambdaMax()

Description copied from interface: CLIKR

Gets the maximum damped factor.

Specified by:

getLambdaMax in interface CLIKR

Returns:

the damped factor.

setLambdaMax

public final void setLambdaMax(double lambdaMax)

Description copied from interface: CLIKR

Sets the maximum damped factor.

Specified by:

setLambdaMax in interface CLIKR

Parameters:

lambdaMax - The damped factor to set.

getPositionError

public final RVector3d getPositionError()

Description copied from interface: CLIKR

Gets the current position error.

Specified by:

getPositionError in interface CLIKR

Returns:

the position error vector.

getJointsPosition

public final RVector getJointsPosition()

Gets the current joints position.

Specified by:

getJointsPosition in interface CLIKR

Returns:

the joints position vector.

getJointsVelocity

public final RVector getJointsVelocity()

Gets the current joints velocity.

Specified by:

getJointsVelocity in interface CLIKR

Returns:

the joints velocity vector.

step

public void step(RVector pd,
                 RVector ppd)

Compute the joints position and velocity from a given desired end effector position and velocity. The joints velocity is computed as:

the joints position is computed by Euler integration:
q(t+dt) = q(t) + q'(t)*dt;

Specified by:

step in interface CLIKR

Parameters:

pd - the RVector of desired end effector position.

ppd - the RVector of desired end effector velocity.

step

public void step(RVector pd,
                 RVector ppd,
                 ConstraintVelocity constraint)

Compute the joints position and velocity from a given desired end effector position and velocity with velocity constraint. The joints velocity is computed as:

the joints position is computed by Euler integration:
q(t+dt) = q(t) + q'(t)*dt;

Specified by:

step in interface CLIKR

Parameters:

pd - the RVector of desired end effector position.

ppd - the RVector of desired end effector velocity.

constraint - the velocity constraint class.

See Also:

ConstraintVelocity