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vpForceTwistMatrix Class Reference

#include <visp3/core/vpForceTwistMatrix.h>

+ Inheritance diagram for vpForceTwistMatrix:

Public Member Functions

 vpForceTwistMatrix ()
 
 vpForceTwistMatrix (const vpForceTwistMatrix &F)
 
 vpForceTwistMatrix (const vpHomogeneousMatrix &M)
 
 vpForceTwistMatrix (const vpTranslationVector &t, const vpThetaUVector &thetau)
 
 vpForceTwistMatrix (const vpTranslationVector &t, const vpRotationMatrix &R)
 
 vpForceTwistMatrix (const double tx, const double ty, const double tz, const double tux, const double tuy, const double tuz)
 
virtual ~vpForceTwistMatrix ()
 
vpForceTwistMatrix buildFrom (const vpTranslationVector &t, const vpRotationMatrix &R)
 
vpForceTwistMatrix buildFrom (const vpTranslationVector &t, const vpThetaUVector &thetau)
 
vpForceTwistMatrix buildFrom (const vpHomogeneousMatrix &M)
 
void eye ()
 
vpForceTwistMatrix operator* (const vpForceTwistMatrix &F) const
 
vpMatrix operator* (const vpMatrix &M) const
 
vpColVector operator* (const vpColVector &H) const
 
vpForceTwistMatrixoperator= (const vpForceTwistMatrix &H)
 
int print (std::ostream &s, unsigned int length, char const *intro=0) const
 
void resize (const unsigned int nrows, const unsigned int ncols, const bool flagNullify=true)
 
Deprecated functions
vp_deprecated void init ()
 
vp_deprecated void setIdentity ()
 
Inherited functionalities from vpArray2D
double getMinValue () const
 
double getMaxValue () const
 
unsigned int getRows () const
 
unsigned int getCols () const
 
unsigned int size () const
 
double * operator[] (unsigned int i)
 
double * operator[] (unsigned int i) const
 

Static Public Member Functions

Inherited I/O from vpArray2D with Static Public Member Functions
static bool load (const std::string &filename, vpArray2D< double > &A, const bool binary=false, char *header=NULL)
 
static bool loadYAML (const std::string &filename, vpArray2D< double > &A, char *header=NULL)
 
static bool save (const std::string &filename, const vpArray2D< double > &A, const bool binary=false, const char *header="")
 
static bool saveYAML (const std::string &filename, const vpArray2D< double > &A, const char *header="")
 

Public Attributes

double * data
 

Protected Attributes

unsigned int rowNum
 
unsigned int colNum
 
double ** rowPtrs
 
unsigned int dsize
 

Related Functions

(Note that these are not member functions.)

enum  vpGEMMmethod
 

Detailed Description

Implementation of a force/torque twist matrix and operations on such kind of matrices.

Class that consider the particular case of twist transformation matrix that allows to transform a force/troque vector from one frame to an other.

The vpForceTwistMatrix class is derived from vpArray2D<double>.

The twist transformation matrix that allows to transform the force/torque vector expressed at frame ${\cal F}_b$ into the frame ${\cal F}_a$ is a 6 by 6 matrix defined as

\[ ^a{\bf F}_b = \left[ \begin{array}{cc} ^a{\bf R}_b & {\bf 0}_{3\times 3}\\ {[^a{\bf t}_b]}_{\times} \; ^a{\bf R}_b & ^a{\bf R}_b \end{array} \right] \]

$ ^a{\bf R}_b $ is a rotation matrix and $ ^a{\bf t}_b $ is a translation vector.

The code belows shows for example how to convert a force/torque skew from probe frame to a sensor frame.

#include <visp3/core/vpColVector.h>
#include <visp3/core/vpForceTwistMatrix.h>
int main()
{
vpForceTwistMatrix sFp; // Twist transformation matrix from sensor to probe frame
vpHomogeneousMatrix sMp; // Force/torque sensor frame to probe frame transformation
// ... sMp need here to be initialized
sFp.buildFrom(sMp);
vpColVector p_H(6); // Force/torque skew in the probe frame: fx,fy,fz,tx,ty,tz
// ... p_H should here have an initial value
vpColVector s_H(6); // Force/torque skew in the sensor frame: fx,fy,fz,tx,ty,tz
// Compute the value of the force/torque in the sensor frame
s_H = sFp * p_H;
}
Examples:
testVirtuoseHapticBox.cpp.

Definition at line 102 of file vpForceTwistMatrix.h.

Constructor & Destructor Documentation

vpForceTwistMatrix::vpForceTwistMatrix ( )

Initialize a force/torque twist transformation matrix to identity.

Definition at line 93 of file vpForceTwistMatrix.cpp.

References eye().

vpForceTwistMatrix::vpForceTwistMatrix ( const vpForceTwistMatrix F)

Initialize a force/torque twist transformation matrix from another force/torque twist matrix.

Parameters
F: Force/torque twist matrix used as initializer.

Definition at line 106 of file vpForceTwistMatrix.cpp.

vpForceTwistMatrix::vpForceTwistMatrix ( const vpHomogeneousMatrix M)

Initialize a force/torque twist transformation matrix from an homogeneous matrix. Given the homogeneous transformation

\[ ^a{\bf M}_b = \left(\begin{array}{cc} ^a{\bf R}_b & ^a{\bf t}_b\\ 0 & 1 \end{array} \right) \]

the force/torque twist matrix is given by :

\[ ^a{\bf F}_b = \left[\begin{array}{cc} ^a{\bf R}_b & {\bf 0}_{3\times 3}\\ {[^a{\bf t}_b]}_{\times} \; ^a{\bf R}_b & ^a{\bf R}_b \end{array} \right] \]

Parameters
M: Homogeneous matrix $^a{\bf M}_b$ used to initialize the twist transformation matrix.

Definition at line 136 of file vpForceTwistMatrix.cpp.

References buildFrom().

vpForceTwistMatrix::vpForceTwistMatrix ( const vpTranslationVector t,
const vpThetaUVector thetau 
)

Initialize a force/torque twist transformation matrix from a translation vector t and a rotation vector with $\theta u $ parametrization.

Parameters
t: Translation vector.
thetau: $\theta u$ rotation vector.

Definition at line 152 of file vpForceTwistMatrix.cpp.

References buildFrom().

vpForceTwistMatrix::vpForceTwistMatrix ( const vpTranslationVector t,
const vpRotationMatrix R 
)

Initialize a force/torque twist transformation matrix from a translation vector t and a rotation matrix R.

Parameters
t: Translation vector.
R: Rotation matrix.

Definition at line 169 of file vpForceTwistMatrix.cpp.

References buildFrom().

vpForceTwistMatrix::vpForceTwistMatrix ( const double  tx,
const double  ty,
const double  tz,
const double  tux,
const double  tuy,
const double  tuz 
)

Initialize a force/torque twist transformation matrix from a translation vector ${\bf t}=(t_x, t_y, t_z)^T$ and a rotation vector with $\theta {\bf u}=(\theta u_x, \theta u_y, \theta u_z)^T $ parametrization.

Parameters
tx,ty,tz: Translation vector in meters.
tux,tuy,tuz: $\theta {\bf u}$ rotation vector expressed in radians.

Definition at line 185 of file vpForceTwistMatrix.cpp.

References buildFrom().

virtual vpForceTwistMatrix::~vpForceTwistMatrix ( )
inlinevirtual

Destructor.

Definition at line 121 of file vpForceTwistMatrix.h.

Member Function Documentation

vpForceTwistMatrix vpForceTwistMatrix::buildFrom ( const vpTranslationVector t,
const vpRotationMatrix R 
)

Build a force/torque twist transformation matrix from a translation vector t and a rotation matrix R.

Parameters
t: Translation vector.
R: Rotation matrix.

Definition at line 337 of file vpForceTwistMatrix.cpp.

References vpTranslationVector::skew().

Referenced by buildFrom(), and vpForceTwistMatrix().

vpForceTwistMatrix vpForceTwistMatrix::buildFrom ( const vpTranslationVector tv,
const vpThetaUVector thetau 
)

Initialize a force/torque twist transformation matrix from a translation vector t and a rotation vector with $\theta u $ parametrization.

Parameters
tv: Translation vector.
thetau: $\theta {\bf u}$ rotation vector.

Definition at line 364 of file vpForceTwistMatrix.cpp.

References vpRotationMatrix::buildFrom(), and buildFrom().

vpForceTwistMatrix vpForceTwistMatrix::buildFrom ( const vpHomogeneousMatrix M)

Initialize a force/torque twist transformation matrix from an homogeneous matrix $M$ with

\[ {\bf M} = \left[\begin{array}{cc} {\bf R} & {\bf t} \\ {\bf 0}_{1\times 3} & 1 \end{array} \right] \]

Parameters
M: Homogeneous matrix $M$ used to initialize the force/torque twist transformation matrix.

Definition at line 385 of file vpForceTwistMatrix.cpp.

References buildFrom(), and vpHomogeneousMatrix::extract().

void vpForceTwistMatrix::eye ( )

Initialize the force/torque 6 by 6 twist matrix to identity.

Definition at line 78 of file vpForceTwistMatrix.cpp.

Referenced by setIdentity(), and vpForceTwistMatrix().

double vpArray2D< double >::getMaxValue ( ) const
inherited

Return the array max value.

Examples:
servoMomentImage.cpp.
double vpArray2D< double >::getMinValue ( ) const
inherited

Return the array min value.

Examples:
servoMomentImage.cpp.
vp_deprecated void vpForceTwistMatrix::init ( )
inline
Deprecated:
Provided only for compat with previous releases. This function does nothing.

Definition at line 165 of file vpForceTwistMatrix.h.

static bool vpArray2D< double >::load ( const std::string &  filename,
vpArray2D< double > &  A,
const bool  binary = false,
char *  header = NULL 
)
inlinestaticinherited

Load a matrix from a file.

Parameters
filename: Absolute file name.
A: Array to be loaded
binary: If true the matrix is loaded from a binary file, else from a text file.
header: Header of the file is loaded in this parameter.
Returns
Returns true if success.
See Also
save()

Definition at line 308 of file vpArray2D.h.

References vpException::badValue, and vpArray2D< Type >::resize().

static bool vpArray2D< double >::loadYAML ( const std::string &  filename,
vpArray2D< double > &  A,
char *  header = NULL 
)
inlinestaticinherited

Load an array from a YAML-formatted file.

Parameters
filename: absolute file name.
A: array to be loaded from the file.
header: header of the file is loaded in this parameter.
Returns
Returns true on success.
See Also
saveYAML()

Definition at line 417 of file vpArray2D.h.

References vpArray2D< Type >::resize().

vpForceTwistMatrix vpForceTwistMatrix::operator* ( const vpForceTwistMatrix F) const

Operator that allows to multiply a skew transformation matrix by an other skew transformation matrix.

#include <visp3/core/vpForceTwistMatrix.h>
int main()
{
// ... initialize the force/torque twist transformations aFb and bFc
// Compute the force/torque transformation from frame a to c
vpForceTwistMatrix aFc = aFb * bFc;
}

Definition at line 213 of file vpForceTwistMatrix.cpp.

References vpArray2D< double >::rowPtrs, and vpArray2D< Type >::rowPtrs.

vpMatrix vpForceTwistMatrix::operator* ( const vpMatrix M) const

Operator that allows to multiply a skew transformation matrix by a matrix.

Exceptions
vpException::dimensionErrorIf M is not a 6 rows dimension matrix.

Definition at line 235 of file vpForceTwistMatrix.cpp.

References vpException::dimensionError, vpArray2D< Type >::getCols(), vpArray2D< Type >::getRows(), and vpArray2D< double >::rowPtrs.

vpColVector vpForceTwistMatrix::operator* ( const vpColVector H) const

Operator that allows to multiply a skew transformation matrix by a column vector.

Parameters
H: Force/torque skew vector ${\bf H} = [f_x, f_y, f_z, \tau_x, \tau_y, \tau_z] $.

For example, this operator can be used to convert a force/torque skew from sensor frame into the probe frame :

$^p{\bf H} = ^p{\bf F}_s \; ^s{\bf H}$

The example below shows how to handle that transformation.

#include <visp3/core/vpConfig.h>
#include <visp3/robot/vpRobotViper850.h>
#include <visp3/core/vpColVector.h>
#include <visp3/core/vpForceTwistMatrix.h>
int main()
{
#ifdef VISP_HAVE_VIPER850
vpColVector sH = robot.getForceTorque(sH); // Get the force/torque measures
#endif
// Set the transformation from sensor frame to the probe frame
pMs[2][3] = -0.262; // tz only
// Set the force/torque twist transformation
vpForceTwistMatrix pFs(pMs); // Twist transformation matrix from probe to sensor frame
// Compute the resulting force/torque in the probe frame
vpColVector pH(6); // Force/torque in the probe frame
pH = pFs * sH;
return 0;
}
Exceptions
vpException::dimensionErrorIf $ \bf H $is not a 6 dimension vector.

Definition at line 304 of file vpForceTwistMatrix.cpp.

References vpException::dimensionError, vpArray2D< Type >::getRows(), and vpArray2D< double >::rowPtrs.

vpForceTwistMatrix & vpForceTwistMatrix::operator= ( const vpForceTwistMatrix M)

Copy operator.

Parameters
M: Force/torque twist matrix to copy.

Definition at line 62 of file vpForceTwistMatrix.cpp.

References vpArray2D< double >::rowPtrs, and vpArray2D< Type >::rowPtrs.

double * vpArray2D< double >::operator[] ( unsigned int  i)
inlineinherited

Set element $A_{ij} = x$ using A[i][j] = x.

Definition at line 259 of file vpArray2D.h.

References vpArray2D< Type >::rowPtrs.

double * vpArray2D< double >::operator[] ( unsigned int  i) const
inlineinherited

Get element $x = A_{ij}$ using x = A[i][j].

Definition at line 261 of file vpArray2D.h.

References vpArray2D< Type >::rowPtrs.

int vpForceTwistMatrix::print ( std::ostream &  s,
unsigned int  length,
char const *  intro = 0 
) const

Pretty print a velocity twist matrix. The data are tabulated. The common widths before and after the decimal point are set with respect to the parameter maxlen.

Parameters
sStream used for the printing.
lengthThe suggested width of each matrix element. The actual width grows in order to accomodate the whole integral part, and shrinks if the whole extent is not needed for all the numbers.
introThe introduction which is printed before the matrix. Can be set to zero (or omitted), in which case the introduction is not printed.
Returns
Returns the common total width for all matrix elements
See Also
std::ostream &operator <<(ostream &s,const vpMatrix &m)

Definition at line 416 of file vpForceTwistMatrix.cpp.

References vpArray2D< double >::getCols(), vpArray2D< double >::getRows(), and vpMath::maximum().

void vpForceTwistMatrix::resize ( const unsigned int  nrows,
const unsigned int  ncols,
const bool  flagNullify = true 
)
inline

This function is not applicable to a velocity twist matrix that is always a 6-by-6 matrix.

Exceptions
vpException::fatalErrorWhen this function is called.

Definition at line 147 of file vpForceTwistMatrix.h.

References vpException::fatalError.

static bool vpArray2D< double >::save ( const std::string &  filename,
const vpArray2D< double > &  A,
const bool  binary = false,
const char *  header = "" 
)
inlinestaticinherited

Save a matrix to a file.

Parameters
filename: Absolute file name.
A: Array to be saved.
binary: If true the matrix is saved in a binary file, else a text file.
header: Optional line that will be saved at the beginning of the file.
Returns
Returns true if success.

Warning : If you save the matrix as in a text file the precision is less than if you save it in a binary file.

See Also
load()

Definition at line 499 of file vpArray2D.h.

References vpArray2D< Type >::getCols(), and vpArray2D< Type >::getRows().

static bool vpArray2D< double >::saveYAML ( const std::string &  filename,
const vpArray2D< double > &  A,
const char *  header = "" 
)
inlinestaticinherited

Save an array in a YAML-formatted file.

Parameters
filename: absolute file name.
A: array to be saved in the file.
header: optional lines that will be saved at the beginning of the file. Should be YAML-formatted and will adapt to the indentation if any.
Returns
Returns true if success.

Here is an example of outputs.

vpArray2D::saveYAML("matrix.yml", M, "example: a YAML-formatted header");
vpArray2D::saveYAML("matrixIndent.yml", M, "example:\n - a YAML-formatted header\n - with inner indentation");

Content of matrix.yml:

example: a YAML-formatted header
rows: 3
cols: 4
- [0, 0, 0, 0]
- [0, 0, 0, 0]
- [0, 0, 0, 0]

Content of matrixIndent.yml:

example:
- a YAML-formatted header
- with inner indentation
rows: 3
cols: 4
- [0, 0, 0, 0]
- [0, 0, 0, 0]
- [0, 0, 0, 0]
See Also
loadYAML()

Definition at line 588 of file vpArray2D.h.

References vpArray2D< Type >::getCols(), and vpArray2D< Type >::getRows().

void vpForceTwistMatrix::setIdentity ( )
Deprecated:
You should rather use eye().
Deprecated:
You should rather use eye().

Set the twist transformation matrix to identity.

See Also
eye()

Definition at line 510 of file vpForceTwistMatrix.cpp.

References eye().

Friends And Related Function Documentation

enum vpGEMMmethod
related

Enumeration of the operations applied on matrices in vpGEMM() function.

Operations are :

  • VP_GEMM_A_T to use the transpose matrix of A instead of the matrix A
  • VP_GEMM_B_T to use the transpose matrix of B instead of the matrix B
  • VP_GEMM_C_T to use the transpose matrix of C instead of the matrix C

Definition at line 57 of file vpGEMM.h.

Member Data Documentation

double * vpArray2D< double >::data
inherited

Address of the first element of the data array.

Examples:
testDisplacement.cpp, testMatrix.cpp, testPoseVector.cpp, and testTranslationVector.cpp.

Definition at line 84 of file vpArray2D.h.

Referenced by vpMatrix::AtA(), vpHomogeneousMatrix::buildFrom(), vpRzyzVector::buildFrom(), vpRzyxVector::buildFrom(), vpRxyzVector::buildFrom(), vpThetaUVector::buildFrom(), vpSubColVector::checkParentStatus(), vpSubRowVector::checkParentStatus(), vpSubMatrix::checkParentStatus(), vpColVector::clear(), vpHomogeneousMatrix::convert(), vpTranslationVector::euclideanNorm(), vpRowVector::euclideanNorm(), vpMatrix::euclideanNorm(), vpMatrix::expm(), vpThetaUVector::extract(), vpThetaUVector::getTheta(), vpThetaUVector::getU(), vpSubColVector::init(), vpSubRowVector::init(), vpSubMatrix::init(), vpTranslationVector::operator*(), vpRowVector::operator*(), vpColVector::operator*(), vpHomography::operator*(), vpTranslationVector::operator-(), vpRowVector::operator-(), vpColVector::operator-(), vpTranslationVector::operator/(), vpRowVector::operator/(), vpColVector::operator/(), vpHomography::operator/(), vpHomography::operator/=(), vpSubColVector::operator=(), vpSubRowVector::operator=(), vpQuaternionVector::operator=(), vpTranslationVector::operator=(), vpRowVector::operator=(), vpRzyzVector::operator=(), vpRzyxVector::operator=(), vpRxyzVector::operator=(), vpColVector::operator=(), vpMatrix::operator=(), vpThetaUVector::operator=(), vpColVector::operator[](), vpRowVector::reshape(), vpColVector::reshape(), vpQuaternionVector::set(), vpMatrix::stackRows(), vpColVector::sum(), vpColVector::sumSquare(), vpRotationVector::t(), vpTranslationVector::t(), vpPoseVector::t(), vpRowVector::t(), vpColVector::t(), vpQuaternionVector::vpQuaternionVector(), vpRxyzVector::vpRxyzVector(), vpRzyxVector::vpRzyxVector(), vpRzyzVector::vpRzyzVector(), vpThetaUVector::vpThetaUVector(), vpQuaternionVector::w(), vpQuaternionVector::x(), vpQuaternionVector::y(), vpQuaternionVector::z(), vpSubColVector::~vpSubColVector(), vpSubMatrix::~vpSubMatrix(), and vpSubRowVector::~vpSubRowVector().

unsigned int vpArray2D< double >::rowNum
protectedinherited

Number of rows in the array.

Definition at line 74 of file vpArray2D.h.

Referenced by vpMatrix::AAt(), vpMatrix::AtA(), vpColVector::clear(), vpMatrix::diag(), vpMatrix::eigenValues(), vpMatrix::expm(), vpColVector::extract(), vpMatrix::eye(), vpColVector::infinityNorm(), vpMatrix::infinityNorm(), vpSubColVector::init(), vpSubRowVector::init(), vpSubMatrix::init(), vpMatrix::insert(), vpMatrix::inverseByCholesky(), vpMatrix::inverseByLU(), vpMatrix::inverseByQR(), vpRotationMatrix::operator*(), vpTranslationVector::operator*(), vpHomogeneousMatrix::operator*(), vpColVector::operator*(), vpMatrix::operator*(), vpRotationMatrix::operator*=(), vpTranslationVector::operator*=(), vpColVector::operator*=(), vpMatrix::operator*=(), vpColVector::operator+(), vpColVector::operator+=(), vpMatrix::operator+=(), vpColVector::operator-(), vpColVector::operator-=(), vpMatrix::operator-=(), vpColVector::operator/(), vpMatrix::operator/(), vpTranslationVector::operator/=(), vpColVector::operator/=(), vpMatrix::operator/=(), vpMatrix::operator<<(), vpColVector::operator<<(), vpSubColVector::operator=(), vpSubRowVector::operator=(), vpSubMatrix::operator=(), vpTranslationVector::operator=(), vpRowVector::operator=(), vpColVector::operator=(), vpMatrix::operator=(), vpColVector::reshape(), vpMatrix::setIdentity(), vpMatrix::stack(), vpColVector::stack(), vpMatrix::stackColumns(), vpMatrix::stackRows(), vpColVector::sum(), vpMatrix::sum(), vpRotationVector::sumSquare(), vpTranslationVector::sumSquare(), vpColVector::sumSquare(), vpMatrix::sumSquare(), vpTranslationVector::t(), vpPoseVector::t(), vpColVector::t(), vpMatrix::t(), and vpMatrix::transpose().