OrientationCost Class Reference

Detailed Description

Implements a cost of the form c * (1 - cos(θ)), where θ is the angle between the orientation of frame A and the orientation of frame B, and c is a cost scaling.

#include <drake/multibody/inverse_kinematics/orientation_cost.h>

Public Member Functions
	OrientationCost (const MultibodyPlant< double > *plant, const Frame< double > &frameAbar, const math::RotationMatrix< double > &R_AbarA, const Frame< double > &frameBbar, const math::RotationMatrix< double > &R_BbarB, double c, systems::Context< double > *plant_context)
	Constructs OrientationCost object.
	OrientationCost (const MultibodyPlant< AutoDiffXd > *plant, const Frame< AutoDiffXd > &frameAbar, const math::RotationMatrix< double > &R_AbarA, const Frame< AutoDiffXd > &frameBbar, const math::RotationMatrix< double > &R_BbarB, double c, systems::Context< AutoDiffXd > *plant_context)
	Overloaded constructor.
	~OrientationCost () override
Does not allow copy, move, or assignment
	OrientationCost (const OrientationCost &)=delete
OrientationCost &	operator= (const OrientationCost &)=delete
	OrientationCost (OrientationCost &&)=delete
OrientationCost &	operator= (OrientationCost &&)=delete
Public Member Functions inherited from Cost
	Cost (const Cost &)=delete
Cost &	operator= (const Cost &)=delete
	Cost (Cost &&)=delete
Cost &	operator= (Cost &&)=delete
Public Member Functions inherited from EvaluatorBase
virtual	~EvaluatorBase ()
void	Eval (const Eigen::Ref< const Eigen::VectorXd > &x, Eigen::VectorXd *y) const
	Evaluates the expression.
void	Eval (const Eigen::Ref< const AutoDiffVecXd > &x, AutoDiffVecXd *y) const
	Evaluates the expression.
void	Eval (const Eigen::Ref< const VectorX< symbolic::Variable > > &x, VectorX< symbolic::Expression > *y) const
	Evaluates the expression.
void	set_description (const std::string &description)
	Set a human-friendly description for the evaluator.
const std::string &	get_description () const
	Getter for a human-friendly description for the evaluator.
std::ostream &	Display (std::ostream &os, const VectorX< symbolic::Variable > &vars) const
	Formats this evaluator into the given stream using vars for the bound decision variable names.
std::ostream &	Display (std::ostream &os) const
	Formats this evaluator into the given stream, without displaying the decision variables it is bound to.
std::string	ToLatex (const VectorX< symbolic::Variable > &vars, int precision=3) const
	Returns a LaTeX string describing this evaluator.
int	num_vars () const
	Getter for the number of variables, namely the number of rows in x, as used in Eval(x, y).
int	num_outputs () const
	Getter for the number of outputs, namely the number of rows in y, as used in Eval(x, y).
void	SetGradientSparsityPattern (const std::vector< std::pair< int, int > > &gradient_sparsity_pattern)
	Set the sparsity pattern of the gradient matrix ∂y/∂x (the gradient of y value in Eval, w.r.t x in Eval) .
const std::optional< std::vector< std::pair< int, int > > > &	gradient_sparsity_pattern () const
	Returns the vector of (row_index, col_index) that contains all the entries in the gradient of Eval function (∂y/∂x) whose value could be non-zero, namely if ∂yᵢ/∂xⱼ could be non-zero, then the pair (i, j) is in gradient_sparsity_pattern.
bool	is_thread_safe () const
	Returns whether it is safe to call Eval in parallel.
	EvaluatorBase (const EvaluatorBase &)=delete
EvaluatorBase &	operator= (const EvaluatorBase &)=delete
	EvaluatorBase (EvaluatorBase &&)=delete
EvaluatorBase &	operator= (EvaluatorBase &&)=delete

Additional Inherited Members
Protected Member Functions inherited from Cost
	Cost (int num_vars, const std::string &description="")
	Constructs a cost evaluator.
Protected Member Functions inherited from EvaluatorBase
	EvaluatorBase (int num_outputs, int num_vars, const std::string &description="")
	Constructs a evaluator.
virtual std::ostream &	DoDisplay (std::ostream &os, const VectorX< symbolic::Variable > &vars) const
	NVI implementation of Display.
virtual std::string	DoToLatex (const VectorX< symbolic::Variable > &vars, int precision) const
void	set_num_outputs (int num_outputs)
void	set_is_thread_safe (bool is_thread_safe)

Constructor & Destructor Documentation

OrientationCost() [1/4]

OrientationCost ( const OrientationCost & )

delete

OrientationCost() [2/4]

OrientationCost ( OrientationCost && )

delete

OrientationCost() [3/4]

OrientationCost	(	const MultibodyPlant< double > *	plant,
		const Frame< double > &	frameAbar,
		const math::RotationMatrix< double > &	R_AbarA,
		const Frame< double > &	frameBbar,
		const math::RotationMatrix< double > &	R_BbarB,
		double	c,
		systems::Context< double > *	plant_context )

Constructs OrientationCost object.

Parameters

plant	The MultibodyPlant on which the cost is implemented. plant should be alive during the lifetime of this cost.
frameAbar	A frame on the MultibodyPlant.
R_AbarA	The rotation matrix describing the orientation of frame A relative to Abar.
frameBbar	A frame on the MultibodyPlant.
R_BbarB	The rotation matrix describing the orientation of frame B relative to Bbar.
c	A scalar cost weight.
plant_context	A context for the plant.

Exceptions

std::exception	if plant is nullptr.
std::exception	if plant_context is nullptr.

OrientationCost() [4/4]

OrientationCost	(	const MultibodyPlant< AutoDiffXd > *	plant,
		const Frame< AutoDiffXd > &	frameAbar,
		const math::RotationMatrix< double > &	R_AbarA,
		const Frame< AutoDiffXd > &	frameBbar,
		const math::RotationMatrix< double > &	R_BbarB,
		double	c,
		systems::Context< AutoDiffXd > *	plant_context )

Overloaded constructor.

Same as the constructor with the double version (using MultibodyPlant<double> and Context<double>). Except the gradient of the cost is computed from autodiff.

~OrientationCost()

~OrientationCost ( )

override

Member Function Documentation

operator=() [1/2]

OrientationCost & operator= ( const OrientationCost & )

delete

operator=() [2/2]

OrientationCost & operator= ( OrientationCost && )

delete

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

• drake/multibody/inverse_kinematics/orientation_cost.h