tasks::qp::DamperJointLimitsConstr Class Reference

#include <Tasks/QPConstr.h>

Inheritance diagram for tasks::qp::DamperJointLimitsConstr:

Collaboration diagram for tasks::qp::DamperJointLimitsConstr:

Public Member Functions
	DamperJointLimitsConstr (const std::vector< rbd::MultiBody > &mbs, int robotIndex, const QBound &qBound, const AlphaBound &aBound, double interPercent, double securityPercent, double damperOffset, double step)
	DamperJointLimitsConstr (const std::vector< rbd::MultiBody > &mbs, int robotIndex, const QBound &qBound, const AlphaBound &aBound, const AlphaDBound &aDBound, double interPercent, double securityPercent, double damperOffset, double step)
	DamperJointLimitsConstr (const std::vector< rbd::MultiBody > &mbs, int robotIndex, const QBound &qBound, const AlphaBound &aBound, const AlphaDBound &aDBound, const AlphaDDBound &aDDBound, double interPercent, double securityPercent, double damperOffset, double step)
virtual void	updateNrVars (const std::vector< rbd::MultiBody > &mbs, const SolverData &data) override
virtual void	update (const std::vector< rbd::MultiBody > &mbs, const std::vector< rbd::MultiBodyConfig > &mbcs, const SolverData &data) override
virtual std::string	nameBound () const override
virtual std::string	descBound (const std::vector< rbd::MultiBody > &mbs, int line) override
virtual int	beginVar () const override
virtual const Eigen::VectorXd &	Lower () const override
virtual const Eigen::VectorXd &	Upper () const override
double	computeDamping (double alpha, double dist, double iDist, double sDist)
	compute damping that avoid speed jump More...
double	computeDamper (double dist, double iDist, double sDist, double damping)
Public Member Functions inherited from tasks::qp::ConstraintFunction< Bound >
virtual	~ConstraintFunction () override
void	addToSolver (QPSolver &sol)
void	addToSolver (const std::vector< rbd::MultiBody > &mbs, QPSolver &sol)
void	removeFromSolver (QPSolver &sol)
Public Member Functions inherited from tasks::qp::Constraint
virtual	~Constraint ()

Detailed Description

Avoid to reach articular position and velocity limits based on a velocity damper. For each articulation \( j \):

\[ \frac{\max(-\xi \frac{\underline{d} - d_s}{d_i - d_s}, \underline{\alpha}_{j}) - \alpha_{j}}{\Delta_{dt}} \leq \dot{\alpha}_{j} \leq \frac{\min(\xi \frac{\overline{d} - d_s}{d_i - d_s}, \overline{\alpha}_{j}) - \alpha_{j}}{\Delta_{dt}} \]

with \( \underline{d} \) and \( \overline{d} \) the distance to the lower and upper articular position bound, \( d_i \) the interactive distance, \( d_s \) the security distance and \( \xi \) the damper.

The damper \( \xi \) is calculated automatically each time the distance \( \underline{d} \) or \( \overline{d} \) go below the interactive distance \( d_i \) with the following formula:

\[ \xi = -\frac{d_i - d_s}{d - d_s}\alpha + \xi_{\text{off}} \]

This behavior give the better stability and we usually use the following values:

• \( d_i = 0.1 (\overline{q} - \underline{q}) \)
• \( d_s = 0.01 (\overline{q} - \underline{q}) \)
• \( \xi_{\text{off}} = 0.5 \)

Constructor & Destructor Documentation

DamperJointLimitsConstr() [1/3]

tasks::qp::DamperJointLimitsConstr::DamperJointLimitsConstr	(	const std::vector< rbd::MultiBody > &	mbs,
		int	robotIndex,
		const QBound &	qBound,
		const AlphaBound &	aBound,
		double	interPercent,
		double	securityPercent,
		double	damperOffset,
		double	step
	)

Parameters

mbs	Multi-robot system.
robotIndex	Constrained robot Index in mbs.
qBound	Articular position bounds.
aBound	Articular velocity bounds.
interPercent	\( interPercent (\overline{q} - \underline{q}) \)
securityPercent	\( securityPercent (\overline{q} - \underline{q}) \)
damperOffset	\( \xi_{\text{off}} \)
step	Time step in second.

DamperJointLimitsConstr() [2/3]

tasks::qp::DamperJointLimitsConstr::DamperJointLimitsConstr	(	const std::vector< rbd::MultiBody > &	mbs,
		int	robotIndex,
		const QBound &	qBound,
		const AlphaBound &	aBound,
		const AlphaDBound &	aDBound,
		double	interPercent,
		double	securityPercent,
		double	damperOffset,
		double	step
	)

Parameters

mbs	Multi-robot system.
robotIndex	Constrained robot Index in mbs.
qBound	Articular position bounds.
aBound	Articular velocity bounds.
aDBound	Articular acceleration bounds.
interPercent	\( interPercent (\overline{q} - \underline{q}) \)
securityPercent	\( securityPercent (\overline{q} - \underline{q}) \)
damperOffset	\( \xi_{\text{off}} \)
step	Time step in second.

DamperJointLimitsConstr() [3/3]

tasks::qp::DamperJointLimitsConstr::DamperJointLimitsConstr	(	const std::vector< rbd::MultiBody > &	mbs,
		int	robotIndex,
		const QBound &	qBound,
		const AlphaBound &	aBound,
		const AlphaDBound &	aDBound,
		const AlphaDDBound &	aDDBound,
		double	interPercent,
		double	securityPercent,
		double	damperOffset,
		double	step
	)

Parameters

mbs	Multi-robot system.
robotIndex	Constrained robot Index in mbs.
qBound	Articular position bounds.
aBound	Articular velocity bounds.
aDBound	Articular acceleration bounds.
aDDBound	Articular jerk bounds.
interPercent	\( interPercent (\overline{q} - \underline{q}) \)
securityPercent	\( securityPercent (\overline{q} - \underline{q}) \)
damperOffset	\( \xi_{\text{off}} \)
step	Time step in second.

Member Function Documentation

beginVar()

virtual int tasks::qp::DamperJointLimitsConstr::beginVar ( ) const

overridevirtual

computeDamper()

double tasks::qp::DamperJointLimitsConstr::computeDamper	(	double	dist,
		double	iDist,
		double	sDist,
		double	damping
	)

computeDamping()

double tasks::qp::DamperJointLimitsConstr::computeDamping	(	double	alpha,
		double	dist,
		double	iDist,
		double	sDist
	)

compute damping that avoid speed jump

descBound()

virtual std::string tasks::qp::DamperJointLimitsConstr::descBound ( const std::vector< rbd::MultiBody > &  mbs, int  line  )

overridevirtual

Lower()

virtual const Eigen::VectorXd& tasks::qp::DamperJointLimitsConstr::Lower ( ) const

overridevirtual

nameBound()

virtual std::string tasks::qp::DamperJointLimitsConstr::nameBound ( ) const

overridevirtual

update()

virtual void tasks::qp::DamperJointLimitsConstr::update ( const std::vector< rbd::MultiBody > &  mbs, const std::vector< rbd::MultiBodyConfig > &  mbcs, const SolverData &  data  )

overridevirtual

Implements tasks::qp::Constraint.

updateNrVars()

virtual void tasks::qp::DamperJointLimitsConstr::updateNrVars ( const std::vector< rbd::MultiBody > &  mbs, const SolverData &  data  )

overridevirtual

Implements tasks::qp::Constraint.

Upper()

virtual const Eigen::VectorXd& tasks::qp::DamperJointLimitsConstr::Upper ( ) const

overridevirtual

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

• src/Tasks/QPConstr.h