Detailed Description

Implements the direct collocation constraints for a first-order hold on the input and a cubic polynomial representation of the state trajectories.

Note that the DirectCollocation implementation allocates only ONE of these constraints, but binds that constraint multiple times (with different decision variables, along the trajectory).

#include <drake/planning/trajectory_optimization/direct_collocation.h>

Public Member Functions
	DirectCollocationConstraint (const systems::System< double > &system, const systems::Context< double > &context, std::variant< systems::InputPortSelection, systems::InputPortIndex > input_port_index=systems::InputPortSelection::kUseFirstInputIfItExists, bool assume_non_continuous_states_are_fixed=false)

	DirectCollocationConstraint (const systems::System< AutoDiffXd > &system, systems::Context< AutoDiffXd > context_sample, systems::Context< AutoDiffXd > context_next_sample, systems::Context< AutoDiffXd > *context_collocation, std::variant< systems::InputPortSelection, systems::InputPortIndex > input_port_index=systems::InputPortSelection::kUseFirstInputIfItExists, bool assume_non_continuous_states_are_fixed=false)
	Constructor which supports passing different mutable contexts for the different evaluation times. More...

	~DirectCollocationConstraint () override=default

int	num_states () const

int	num_inputs () const

Does not allow copy, move, or assignment
	DirectCollocationConstraint (const DirectCollocationConstraint &)=delete

DirectCollocationConstraint &	operator= (const DirectCollocationConstraint &)=delete

	DirectCollocationConstraint (DirectCollocationConstraint &&)=delete

DirectCollocationConstraint &	operator= (DirectCollocationConstraint &&)=delete

Public Member Functions inherited from Constraint
template<typename DerivedLB , typename DerivedUB >
	Constraint (int num_constraints, int num_vars, const Eigen::MatrixBase< DerivedLB > &lb, const Eigen::MatrixBase< DerivedUB > &ub, const std::string &description="")
	Constructs a constraint which has `num_constraints` rows, with an input `num_vars` x 1 vector. More...

	Constraint (int num_constraints, int num_vars)
	Constructs a constraint which has `num_constraints` rows, with an input `num_vars` x 1 vector, with no bounds. More...

bool	CheckSatisfied (const Eigen::Ref< const Eigen::VectorXd > &x, double tol=1E-6) const
	Return whether this constraint is satisfied by the given value, `x`. More...

bool	CheckSatisfied (const Eigen::Ref< const AutoDiffVecXd > &x, double tol=1E-6) const

symbolic::Formula	CheckSatisfied (const Eigen::Ref< const VectorX< symbolic::Variable >> &x) const

const Eigen::VectorXd &	lower_bound () const

const Eigen::VectorXd &	upper_bound () const

int	num_constraints () const
	Number of rows in the output constraint. More...

	Constraint (const Constraint &)=delete

Constraint &	operator= (const Constraint &)=delete

	Constraint (Constraint &&)=delete

Constraint &	operator= (Constraint &&)=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. More...

void	Eval (const Eigen::Ref< const AutoDiffVecXd > &x, AutoDiffVecXd *y) const
	Evaluates the expression. More...

void	Eval (const Eigen::Ref< const VectorX< symbolic::Variable >> &x, VectorX< symbolic::Expression > *y) const
	Evaluates the expression. More...

void	set_description (const std::string &description)
	Set a human-friendly description for the evaluator. More...

const std::string &	get_description () const
	Getter for a human-friendly description for the evaluator. More...

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. More...

std::ostream &	Display (std::ostream &os) const
	Formats this evaluator into the given stream, without displaying the decision variables it is bound to. More...

std::string	ToLatex (const VectorX< symbolic::Variable > &vars, int precision=3) const
	Returns a LaTeX string describing this evaluator. More...

int	num_vars () const
	Getter for the number of variables, namely the number of rows in x, as used in Eval(x, y). More...

int	num_outputs () const
	Getter for the number of outputs, namely the number of rows in y, as used in Eval(x, y). More...

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) . More...

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. More...

bool	is_thread_safe () const
	Returns whether it is safe to call Eval in parallel. More...

	EvaluatorBase (const EvaluatorBase &)=delete

EvaluatorBase &	operator= (const EvaluatorBase &)=delete

	EvaluatorBase (EvaluatorBase &&)=delete

EvaluatorBase &	operator= (EvaluatorBase &&)=delete

Protected Member Functions
	DirectCollocationConstraint (std::pair< std::unique_ptr< systems::System< AutoDiffXd >>, std::unique_ptr< systems::Context< AutoDiffXd >>> owned_pair, const systems::System< AutoDiffXd > system, systems::Context< AutoDiffXd > context_sample, systems::Context< AutoDiffXd > context_next_sample, systems::Context< AutoDiffXd > context_collocation, int num_states, int num_inputs, std::variant< systems::InputPortSelection, systems::InputPortIndex > input_port_index, bool assume_non_continuous_states_are_fixed)

void	DoEval (const Eigen::Ref< const Eigen::VectorXd > &x, Eigen::VectorXd *y) const override
	Implements expression evaluation for scalar type double. More...

void	DoEval (const Eigen::Ref< const AutoDiffVecXd > &x, AutoDiffVecXd *y) const override
	Implements expression evaluation for scalar type AutoDiffXd. More...

void	DoEval (const Eigen::Ref< const VectorX< symbolic::Variable >> &x, VectorX< symbolic::Expression > *y) const override
	Implements expression evaluation for scalar type symbolic::Expression. More...

Protected Member Functions inherited from Constraint
void	UpdateLowerBound (const Eigen::Ref< const Eigen::VectorXd > &new_lb)
	Updates the lower bound. More...

void	UpdateUpperBound (const Eigen::Ref< const Eigen::VectorXd > &new_ub)
	Updates the upper bound. More...

void	set_bounds (const Eigen::Ref< const Eigen::VectorXd > &new_lb, const Eigen::Ref< const Eigen::VectorXd > &new_ub)
	Set the upper and lower bounds of the constraint. More...

virtual bool	DoCheckSatisfied (const Eigen::Ref< const Eigen::VectorXd > &x, const double tol) const

virtual bool	DoCheckSatisfied (const Eigen::Ref< const AutoDiffVecXd > &x, const double tol) const

virtual symbolic::Formula	DoCheckSatisfied (const Eigen::Ref< const VectorX< symbolic::Variable >> &x) const

Protected Member Functions inherited from EvaluatorBase
	EvaluatorBase (int num_outputs, int num_vars, const std::string &description="")
	Constructs a evaluator. More...

virtual std::ostream &	DoDisplay (std::ostream &os, const VectorX< symbolic::Variable > &vars) const
	NVI implementation of Display. More...

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

◆ DirectCollocationConstraint() [1/5]

DirectCollocationConstraint ( const DirectCollocationConstraint & )

delete

◆ DirectCollocationConstraint() [2/5]

DirectCollocationConstraint ( DirectCollocationConstraint && )

delete

◆ DirectCollocationConstraint() [3/5]

DirectCollocationConstraint	(	const systems::System< double > &	system,
		const systems::Context< double > &	context,
		std::variant< systems::InputPortSelection, systems::InputPortIndex >	input_port_index = `systems::InputPortSelection::kUseFirstInputIfItExists`,
		bool	assume_non_continuous_states_are_fixed = `false`
	)

See also: DirectCollocation constructor for a description of the parameters.

Exceptions

std::exception if system is not supported by this direct collocation method.

◆ DirectCollocationConstraint() [4/5]

DirectCollocationConstraint	(	const systems::System< AutoDiffXd > &	system,
		systems::Context< AutoDiffXd > *	context_sample,
		systems::Context< AutoDiffXd > *	context_next_sample,
		systems::Context< AutoDiffXd > *	context_collocation,
		std::variant< systems::InputPortSelection, systems::InputPortIndex >	input_port_index = `systems::InputPortSelection::kUseFirstInputIfItExists`,
		bool	assume_non_continuous_states_are_fixed = `false`
	)

Constructor which supports passing different mutable contexts for the different evaluation times.

This can be used to facilitate caching (for instance, if the context_segment_start of one constraint uses the context_segment_end of the previous constraint).

See also: DirectCollocation constructor for a description of the remaining parameters.

Exceptions

std::exception if system is not supported by this direct collocation method.

◆ ~DirectCollocationConstraint()

~DirectCollocationConstraint ( )

overridedefault

◆ DirectCollocationConstraint() [5/5]

DirectCollocationConstraint	(	std::pair< std::unique_ptr< systems::System< AutoDiffXd >>, std::unique_ptr< systems::Context< AutoDiffXd >>>	owned_pair,
		const systems::System< AutoDiffXd > *	system,
		systems::Context< AutoDiffXd > *	context_sample,
		systems::Context< AutoDiffXd > *	context_next_sample,
		systems::Context< AutoDiffXd > *	context_collocation,
		int	num_states,
		int	num_inputs,
		std::variant< systems::InputPortSelection, systems::InputPortIndex >	input_port_index,
		bool	assume_non_continuous_states_are_fixed
	)

protected

Member Function Documentation

◆ DoEval() [1/3]

void DoEval	(	const Eigen::Ref< const Eigen::VectorXd > &	x,
		Eigen::VectorXd *	y
	)		const

overrideprotectedvirtual

Implements expression evaluation for scalar type double.

Parameters

x	Input vector.
y	Output vector.

Precondition: x must be of size num_vars x 1.

Postcondition: y will be of size num_outputs x 1.

Implements EvaluatorBase.

◆ DoEval() [2/3]

void DoEval	(	const Eigen::Ref< const AutoDiffVecXd > &	x,
		AutoDiffVecXd *	y
	)		const

overrideprotectedvirtual

Implements expression evaluation for scalar type AutoDiffXd.

Parameters

x	Input vector.
y	Output vector.

Precondition: x must be of size num_vars x 1.

Postcondition: y will be of size num_outputs x 1.

Implements EvaluatorBase.

◆ DoEval() [3/3]

void DoEval	(	const Eigen::Ref< const VectorX< symbolic::Variable >> &	x,
		VectorX< symbolic::Expression > *	y
	)		const

overrideprotectedvirtual

Implements expression evaluation for scalar type symbolic::Expression.

Parameters

[in]	x	Input vector.
[out]	y	Output vector.

Precondition: x must be of size num_vars x 1.

Postcondition: y will be of size num_outputs x 1.

Implements EvaluatorBase.

◆ num_inputs()

int num_inputs ( ) const

◆ num_states()

int num_states ( ) const

◆ operator=() [1/2]

DirectCollocationConstraint& operator= ( const DirectCollocationConstraint & )

delete

◆ operator=() [2/2]

DirectCollocationConstraint& operator= ( DirectCollocationConstraint && )

delete

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

drake/planning/trajectory_optimization/direct_collocation.h

Detailed Description

Public Member Functions

Protected Member Functions

Constructor & Destructor Documentation

◆ DirectCollocationConstraint() [1/5]

◆ DirectCollocationConstraint() [2/5]

◆ DirectCollocationConstraint() [3/5]

◆ DirectCollocationConstraint() [4/5]

◆ ~DirectCollocationConstraint()

◆ DirectCollocationConstraint() [5/5]

Member Function Documentation

◆ DoEval() [1/3]

◆ DoEval() [2/3]

◆ DoEval() [3/3]

◆ num_inputs()

◆ num_states()

◆ operator=() [1/2]

◆ operator=() [2/2]