Drake
Drake C++ Documentation
PolyhedronConstraint Class Reference

## Detailed Description

Constrain the position of points P1, P2, ..., Pn to satisfy the constraint A.

• [p_FP1; p_FP2; ...; p_FPn] <= b, where p_FPi is the position of point Pi measured and expressed in frame F. Notice the constraint is imposed on the stacked column vector [p_FP1; p_FP2; ...; p_FPn], not on each individual point.

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

## Public Member Functions

PolyhedronConstraint (const MultibodyPlant< double > *plant, const Frame< double > &frameF, const Frame< double > &frameG, const Eigen::Ref< const Eigen::Matrix3Xd > &p_GP, const Eigen::Ref< const Eigen::MatrixXd > &A, const Eigen::Ref< const Eigen::VectorXd > &b, systems::Context< double > *plant_context)
Construct the constraint that the position of P1, ..., Pn satisfy A * [p_FP1; p_FP2; ...; p_FPn] <= b. More...

PolyhedronConstraint (const MultibodyPlant< AutoDiffXd > *plant, const Frame< AutoDiffXd > &frameF, const Frame< AutoDiffXd > &frameG, const Eigen::Ref< const Eigen::Matrix3Xd > &p_GP, const Eigen::Ref< const Eigen::MatrixXd > &A, const Eigen::Ref< const Eigen::VectorXd > &b, systems::Context< AutoDiffXd > *plant_context)

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

PolyhedronConstraintoperator= (const PolyhedronConstraint &)=delete

PolyhedronConstraint (PolyhedronConstraint &&)=delete

PolyhedronConstraintoperator= (PolyhedronConstraint &&)=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

Constraintoperator= (const Constraint &)=delete

Constraint (Constraint &&)=delete

Constraintoperator= (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...

EvaluatorBase (const EvaluatorBase &)=delete

EvaluatorBaseoperator= (const EvaluatorBase &)=delete

EvaluatorBase (EvaluatorBase &&)=delete

EvaluatorBaseoperator= (EvaluatorBase &&)=delete

## Additional Inherited Members

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)

## ◆ PolyhedronConstraint() [1/4]

 PolyhedronConstraint ( const PolyhedronConstraint & )
delete

## ◆ PolyhedronConstraint() [2/4]

 PolyhedronConstraint ( PolyhedronConstraint && )
delete

## ◆ PolyhedronConstraint() [3/4]

 PolyhedronConstraint ( const MultibodyPlant< double > * plant, const Frame< double > & frameF, const Frame< double > & frameG, const Eigen::Ref< const Eigen::Matrix3Xd > & p_GP, const Eigen::Ref< const Eigen::MatrixXd > & A, const Eigen::Ref< const Eigen::VectorXd > & b, systems::Context< double > * plant_context )

Construct the constraint that the position of P1, ..., Pn satisfy A * [p_FP1; p_FP2; ...; p_FPn] <= b.

Parameters
 plant The MultibodyPlant on which the constraint is imposed. plant should be alive during the lifetime of this constraint. frameF The frame in which the position P is measured and expressed frameG The frame in which the point P is rigidly attached. p_GP p_GP.col(i) is the position of the i'th point Pi measured and expressed in frame G. A We impose the constraint A * [p_FP1; p_FP2; ...; p_FPn] <= b.
Precondition
A.cols() = 3 * p_GP.cols();
Parameters
 b We impose the constraint A * [p_FP1; p_FP2; ...; p_FPn] <= b plant_context The Context that has been allocated for this plant. We will update the context when evaluating the constraint. plant_context should be alive during the lifetime of this constraint.

## ◆ PolyhedronConstraint() [4/4]

 PolyhedronConstraint ( const MultibodyPlant< AutoDiffXd > * plant, const Frame< AutoDiffXd > & frameF, const Frame< AutoDiffXd > & frameG, const Eigen::Ref< const Eigen::Matrix3Xd > & p_GP, const Eigen::Ref< const Eigen::MatrixXd > & A, const Eigen::Ref< const Eigen::VectorXd > & b, systems::Context< AutoDiffXd > * plant_context )

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

## ◆ operator=() [1/2]

 PolyhedronConstraint& operator= ( const PolyhedronConstraint & )
delete

## ◆ operator=() [2/2]

 PolyhedronConstraint& operator= ( PolyhedronConstraint && )
delete

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