Impedance controller class. More...

#include <controller.h>

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 .
short	set_Do (const Real Do_i, const short i)
	Assign the rotational impedance damping term .
short	set_Dp (const DiagonalMatrix &Dp_)
	Assign the translational impedance damping matrix .
short	set_Dp (const Real Dp_i, const short i)
	Assign the translational impedance damping term .
short	set_Ko (const DiagonalMatrix &Ko_)
	Assign the rotational impedance stifness matrix .
short	set_Ko (const Real Ko_i, const short i)
	Assign the rotational impedance stifness term .
short	set_Kp (const DiagonalMatrix &Kp_)
	Assign the translational impedance stifness matrix .
short	set_Kp (const Real Kp_i, const short i)
	Assign the translational impedance stifness term .
short	set_Mo (const DiagonalMatrix &Mo_)
	Assign the rotational impedance inertia matrix .
short	set_Mo (const Real Mo_i, const short i)
	Assign the rotational impedance inertia term .
short	set_Mp (const DiagonalMatrix &Mp_)
	Assign the translational impedance inertia matrix .
short	set_Mp (const Real MP_i, const short i)
	Assign the translational impedance inertia term .
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

Impedance::Impedance ( )

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.

Quaternion Impedance::qc

Compliant frame quaternion.

Definition at line 116 of file controller.h.

Quaternion Impedance::qcd

Orientation error (betweem compliant and desired frame) quaternion.

Definition at line 116 of file controller.h.

Quaternion Impedance::qcp

Compliant frame quaternion derivative.

Definition at line 116 of file controller.h.

Quaternion Impedance::qcp_prev

Previous value of qcp.

Definition at line 116 of file controller.h.

Quaternion Impedance::quat

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:

Public Member Functions

Public Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation