iCub::ctrl::Filter Class Reference

IIR and FIR. More...

#include <filters.h>

Inheritance diagram for iCub::ctrl::Filter:

Public Member Functions
	Filter (const yarp::sig::Vector &num, const yarp::sig::Vector &den, const yarp::sig::Vector &y0=yarp::sig::Vector(1, 0.0))
	Creates a filter with specified numerator and denominator coefficients.
virtual void	init (const yarp::sig::Vector &y0)
	Internal state reset.
virtual void	init (const yarp::sig::Vector &y0, const yarp::sig::Vector &u0)
	Internal state reset for filter with zero gain.
void	getCoeffs (yarp::sig::Vector &num, yarp::sig::Vector &den)
	Returns the current filter coefficients.
void	setCoeffs (const yarp::sig::Vector &num, const yarp::sig::Vector &den)
	Sets new filter coefficients.
bool	adjustCoeffs (const yarp::sig::Vector &num, const yarp::sig::Vector &den)
	Modifies the values of existing filter coefficients without varying their lengths.
void	getStates (std::deque< yarp::sig::Vector > &u, std::deque< yarp::sig::Vector > &y)
	Returns the current filter states.
virtual const yarp::sig::Vector &	filt (const yarp::sig::Vector &u)
	Performs filtering on the actual input.
virtual const yarp::sig::Vector &	output () const
	Return current filter output.
Public Member Functions inherited from iCub::ctrl::IFilter
virtual	~IFilter ()
	Destructor.

Protected Attributes
yarp::sig::Vector	b
yarp::sig::Vector	a
yarp::sig::Vector	y
std::deque< yarp::sig::Vector >	uold
std::deque< yarp::sig::Vector >	yold
size_t	n
size_t	m

Detailed Description

IIR and FIR.

Definition at line 76 of file filters.h.

Constructor & Destructor Documentation

Filter()

Filter::Filter	(	const yarp::sig::Vector &	num,
		const yarp::sig::Vector &	den,
		const yarp::sig::Vector &	y0 = yarp::sig::Vector(1,0.0)
	)

Creates a filter with specified numerator and denominator coefficients.

Parameters

num	vector of numerator elements given as increasing power of z^-1.
den	vector of denominator elements given as increasing power of z^-1.
y0	initial output.

Note

den[0] shall not be 0.

Definition at line 26 of file filters.cpp.

Member Function Documentation

adjustCoeffs()

bool Filter::adjustCoeffs	(	const yarp::sig::Vector &	num,
		const yarp::sig::Vector &	den
	)

Modifies the values of existing filter coefficients without varying their lengths.

Parameters

num	vector of numerator elements given as increasing power of z^-1.
den	vector of denominator elements given as increasing power of z^-1.

Returns

true/false on success/fail.

Note

den[0] shall not be 0.

the adjustment is carried out iff num.size() and den.size() match the existing numerator and denominator lengths.

Definition at line 118 of file filters.cpp.

filt()

const Vector & Filter::filt ( const yarp::sig::Vector &  u )

virtual

Performs filtering on the actual input.

Parameters

u	reference to the actual input.

Returns

the corresponding output.

Implements iCub::ctrl::IFilter.

Definition at line 140 of file filters.cpp.

getCoeffs()

void Filter::getCoeffs	(	yarp::sig::Vector &	num,
		yarp::sig::Vector &	den
	)

Returns the current filter coefficients.

Parameters

num	vector of numerator elements returned as increasing power of z^-1.
den	vector of denominator elements returned as increasing power of z^-1.

Definition at line 91 of file filters.cpp.

getStates()

void Filter::getStates	(	std::deque< yarp::sig::Vector > &	u,
		std::deque< yarp::sig::Vector > &	y
	)

Returns the current filter states.

Parameters

u	the current input states.
y	the current output states.

Definition at line 132 of file filters.cpp.

init() [1/2]

virtual void iCub::ctrl::Filter::init ( const yarp::sig::Vector &  y0 )

virtual

Internal state reset.

Parameters

y0	new internal state.

Implements iCub::ctrl::IFilter.

init() [2/2]

virtual void iCub::ctrl::Filter::init ( const yarp::sig::Vector &  y0, const yarp::sig::Vector &  u0  )

virtual

Internal state reset for filter with zero gain.

Parameters

y0	new internal state.
u0	expected next input.

Note

The gain of a digital filter is the sum of the coefficients of its numerator divided by the sum of the coefficients of its denumerator.

output()

virtual const yarp::sig::Vector & iCub::ctrl::Filter::output ( ) const

inlinevirtual

Return current filter output.

Returns

the filter output.

Implements iCub::ctrl::IFilter.

Definition at line 171 of file filters.h.

setCoeffs()

void Filter::setCoeffs	(	const yarp::sig::Vector &	num,
		const yarp::sig::Vector &	den
	)

Sets new filter coefficients.

Parameters

num	vector of numerator elements given as increasing power of z^-1.
den	vector of denominator elements given as increasing power of z^-1.

Note

den[0] shall not be 0.

the internal state is reinitialized to the current output.

Definition at line 99 of file filters.cpp.

Member Data Documentation

a

yarp::sig::Vector iCub::ctrl::Filter::a

protected

Definition at line 80 of file filters.h.

b

yarp::sig::Vector iCub::ctrl::Filter::b

protected

Definition at line 79 of file filters.h.

m

size_t iCub::ctrl::Filter::m

protected

Definition at line 86 of file filters.h.

n

size_t iCub::ctrl::Filter::n

protected

Definition at line 85 of file filters.h.

uold

std::deque<yarp::sig::Vector> iCub::ctrl::Filter::uold

protected

Definition at line 83 of file filters.h.

y

yarp::sig::Vector iCub::ctrl::Filter::y

protected

Definition at line 81 of file filters.h.

yold

std::deque<yarp::sig::Vector> iCub::ctrl::Filter::yold

protected

Definition at line 84 of file filters.h.

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The documentation for this class was generated from the following files:

• icub-main/src/libraries/ctrlLib/include/iCub/ctrl/filters.h
• icub-main/src/libraries/ctrlLib/src/filters.cpp