Public Member Functions | Public Attributes | Private Attributes
Impedance Class Reference

Impedance controller class. More...

#include <controller.h>

List of all members.

Public Member Functions

short control (const ColumnVector &pdpp, const ColumnVector &pdp, const ColumnVector &pd, const ColumnVector &wdp, const ColumnVector &wd, const Quaternion &qd, const ColumnVector &f, const ColumnVector &n, const Real dt)
 Generation of a compliance trajectory.
 Impedance ()
 Constructor.
 Impedance (const Robot_basic &robot, const DiagonalMatrix &Mp_, const DiagonalMatrix &Dp_, const DiagonalMatrix &Kp_, const DiagonalMatrix &Mo_, const DiagonalMatrix &Do_, const DiagonalMatrix &Ko_)
 Constructor.
short set_Do (const DiagonalMatrix &Do_)
 Assign the rotational impedance damping matrix $D_o$.
short set_Do (const Real Do_i, const short i)
 Assign the rotational impedance damping term $D_o(i,i)$.
short set_Dp (const DiagonalMatrix &Dp_)
 Assign the translational impedance damping matrix $D_p$.
short set_Dp (const Real Dp_i, const short i)
 Assign the translational impedance damping term $D_p(i,i)$.
short set_Ko (const DiagonalMatrix &Ko_)
 Assign the rotational impedance stifness matrix $K_o$.
short set_Ko (const Real Ko_i, const short i)
 Assign the rotational impedance stifness term $K_o(i,i)$.
short set_Kp (const DiagonalMatrix &Kp_)
 Assign the translational impedance stifness matrix $K_p$.
short set_Kp (const Real Kp_i, const short i)
 Assign the translational impedance stifness term $K_p(i,i)$.
short set_Mo (const DiagonalMatrix &Mo_)
 Assign the rotational impedance inertia matrix $M_o$.
short set_Mo (const Real Mo_i, const short i)
 Assign the rotational impedance inertia term $M_o(i,i)$.
short set_Mp (const DiagonalMatrix &Mp_)
 Assign the translational impedance inertia matrix $M_p$.
short set_Mp (const Real MP_i, const short i)
 Assign the translational impedance inertia term $M_p(i,i)$.

Public Attributes

ColumnVector pc
 Compliant position.
ColumnVector pcd
 Difference between pc and desired position.
ColumnVector pcdp
 Difference between pcp and desired velocity.
ColumnVector pcp
 Compliant velocity.
ColumnVector pcp_prev
 Previous value of pcp.
ColumnVector pcpp
 Compliant acceleration.
ColumnVector pcpp_prev
 Previous value of pcpp.
Quaternion qc
 Compliant frame quaternion.
Quaternion qcd
 Orientation error (betweem compliant and desired frame) quaternion.
Quaternion qcp
 Compliant frame quaternion derivative.
Quaternion qcp_prev
 Previous value of qcp.
Quaternion quat
 Temporary quaternion.
ColumnVector wc
 Compliant angular velocity.
ColumnVector wcd
 Difference between wc and desired angular velocity.
ColumnVector wcp
 Compliant angular acceleration.
ColumnVector wcp_prev
 Previous value of wcp.

Private Attributes

DiagonalMatrix Do
 Rotational impedance damping matrix.
DiagonalMatrix Dp
 Translational impedance damping matrix.
DiagonalMatrix Ko
 Rotational impedance stifness matrix.
Matrix Ko_prime
 Modified rotational impedance stifness matrix.
DiagonalMatrix Kp
 Translational impedance stifness matrix.
DiagonalMatrix Mo
 Rotational impedance inertia matrix.
DiagonalMatrix Mp
 Translational impedance inertia matrix.

Detailed Description

Impedance controller class.

The implemantation of the impedance controller is made of two section: the first one is the generation of a compliance trajectory and the second one used a position controller to ensure the end effector follow the compliance trajectory (We recommended to used the resolve acceleration controller scheme, implemented in the class Resolved_acc).

This class generate a compliance path given by the translational and the rotational impedance.

\[ M_p\ddot{\tilde{p}} + D_p\dot{\tilde{p}} + K_p\tilde{p} = f \]

\[ M_o\dot{\tilde{\omega}} + D_o\tilde{\omega} + K_o'\tilde{v} = n \]

where $\tilde{x} = x_c - x_d$ and $ v$ is the vector par of the quaternion representing the orientation error between the compliant and desired frame. The orientation error can also be express by rotation matrix, $ \tilde{R} = R_d^TR_c$. The quaternion mathematics are implemented in the Quaternion class. The index $_c$ and $_d$ denote the compliance and the desired respectively.

The impedance parameters $M_p$, $D_p$, $K_p$, $M_o$, $D_o$ and $K_o$ are $3\times 3$ diagonal positive definite matrix

Definition at line 91 of file controller.h.


Constructor & Destructor Documentation

Constructor.

Definition at line 54 of file controller.cpp.

Impedance::Impedance ( const Robot_basic robot,
const DiagonalMatrix &  Mp_,
const DiagonalMatrix &  Dp_,
const DiagonalMatrix &  Kp_,
const DiagonalMatrix &  Mo_,
const DiagonalMatrix &  Do_,
const DiagonalMatrix &  Ko_ 
)

Constructor.

Definition at line 69 of file controller.cpp.


Member Function Documentation

short Impedance::control ( const ColumnVector &  pdpp,
const ColumnVector &  pdp,
const ColumnVector &  pd,
const ColumnVector &  wdp,
const ColumnVector &  wd,
const Quaternion qd,
const ColumnVector &  f,
const ColumnVector &  n,
const Real  dt 
)

Generation of a compliance trajectory.

Parameters:
pdpp,:desired end effector acceleration.
pdp,:desired end effector velocity.
pd,:desired end effector position.
wdp,:desired end effector angular acceleration.
wd,:desired end effector angular velocity.
qd,:desired quaternion.
f,:end effector contact force.
n,:end effector contact moment.
dt,:time frame.
Returns:
short: 0 or WRONG_SIZE if one of the vector input is not $3\times 1$.

The translational and rotational impedance equations are integrated, with input $f$ and $n$ to computed $\ddot{p}_c$ and $\dot{\omega}_c$, $\dot{p}_c$ and $\omega_c$, and then $p_c$ and $q_c$. The compliant quaternion $q_c$ is obtained with the quaternion propagation equations (see Quaternion class).

The quaternion -q represents exactly the same rotation as the quaternion q. The temporay quaternion, quat, is quatd plus a sign correction. It is customary to choose the sign G on q1 so that q0.Gq1 >=0 (the angle between q0 ang Gq1 is acute). This choice avoids extra spinning caused by the interpolated rotations.

Definition at line 298 of file controller.cpp.

short Impedance::set_Do ( const DiagonalMatrix &  Do_)

Assign the rotational impedance damping matrix $D_o$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 232 of file controller.cpp.

short Impedance::set_Do ( const Real  Do_i,
const short  i 
)

Assign the rotational impedance damping term $D_o(i,i)$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 249 of file controller.cpp.

short Impedance::set_Dp ( const DiagonalMatrix &  Dp_)

Assign the translational impedance damping matrix $D_p$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 133 of file controller.cpp.

short Impedance::set_Dp ( const Real  Dp_i,
const short  i 
)

Assign the translational impedance damping term $D_p(i,i)$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 150 of file controller.cpp.

short Impedance::set_Ko ( const DiagonalMatrix &  Ko_)

Assign the rotational impedance stifness matrix $K_o$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 265 of file controller.cpp.

short Impedance::set_Ko ( const Real  Ko_i,
const short  i 
)

Assign the rotational impedance stifness term $K_o(i,i)$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 282 of file controller.cpp.

short Impedance::set_Kp ( const DiagonalMatrix &  Kp_)

Assign the translational impedance stifness matrix $K_p$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 166 of file controller.cpp.

short Impedance::set_Kp ( const Real  Kp_i,
const short  i 
)

Assign the translational impedance stifness term $K_p(i,i)$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 183 of file controller.cpp.

short Impedance::set_Mo ( const DiagonalMatrix &  Mo_)

Assign the rotational impedance inertia matrix $M_o$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 199 of file controller.cpp.

short Impedance::set_Mo ( const Real  Mo_i,
const short  i 
)

Assign the rotational impedance inertia term $M_o(i,i)$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 216 of file controller.cpp.

short Impedance::set_Mp ( const DiagonalMatrix &  Mp_)

Assign the translational impedance inertia matrix $M_p$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 100 of file controller.cpp.

short Impedance::set_Mp ( const Real  Mp_i,
const short  i 
)

Assign the translational impedance inertia term $M_p(i,i)$.

Returns:
short: 0 or WRONG_SIZE if the matrix is not $3\times 3$.

Definition at line 117 of file controller.cpp.


Member Data Documentation

DiagonalMatrix Impedance::Do [private]

Rotational impedance damping matrix.

Definition at line 133 of file controller.h.

DiagonalMatrix Impedance::Dp [private]

Translational impedance damping matrix.

Definition at line 133 of file controller.h.

DiagonalMatrix Impedance::Ko [private]

Rotational impedance stifness matrix.

Definition at line 133 of file controller.h.

Matrix Impedance::Ko_prime [private]

Modified rotational impedance stifness matrix.

Definition at line 139 of file controller.h.

DiagonalMatrix Impedance::Kp [private]

Translational impedance stifness matrix.

Definition at line 133 of file controller.h.

DiagonalMatrix Impedance::Mo [private]

Rotational impedance inertia matrix.

Definition at line 133 of file controller.h.

DiagonalMatrix Impedance::Mp [private]

Translational impedance inertia matrix.

Definition at line 133 of file controller.h.

ColumnVector Impedance::pc

Compliant position.

Definition at line 121 of file controller.h.

ColumnVector Impedance::pcd

Difference between pc and desired position.

Definition at line 121 of file controller.h.

ColumnVector Impedance::pcdp

Difference between pcp and desired velocity.

Definition at line 121 of file controller.h.

ColumnVector Impedance::pcp

Compliant velocity.

Definition at line 121 of file controller.h.

ColumnVector Impedance::pcp_prev

Previous value of pcp.

Definition at line 121 of file controller.h.

ColumnVector Impedance::pcpp

Compliant acceleration.

Definition at line 121 of file controller.h.

ColumnVector Impedance::pcpp_prev

Previous value of pcpp.

Definition at line 121 of file controller.h.

Compliant frame quaternion.

Definition at line 116 of file controller.h.

Orientation error (betweem compliant and desired frame) quaternion.

Definition at line 116 of file controller.h.

Compliant frame quaternion derivative.

Definition at line 116 of file controller.h.

Previous value of qcp.

Definition at line 116 of file controller.h.

Temporary quaternion.

Definition at line 116 of file controller.h.

ColumnVector Impedance::wc

Compliant angular velocity.

Definition at line 121 of file controller.h.

ColumnVector Impedance::wcd

Difference between wc and desired angular velocity.

Definition at line 121 of file controller.h.

ColumnVector Impedance::wcp

Compliant angular acceleration.

Definition at line 121 of file controller.h.

ColumnVector Impedance::wcp_prev

Previous value of wcp.

Definition at line 121 of file controller.h.


The documentation for this class was generated from the following files:
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kni
Author(s): Neuronics AG (see AUTHORS.txt); ROS wrapper by Martin Günther
autogenerated on Tue May 28 2013 14:52:55