Drake
AngleBetweenVectorsConstraint Class Reference

Detailed Description

Constrains that the angle between a vector a and another vector b is between [θ_lower, θ_upper].

a is fixed to a frame A, while b is fixed to a frame B. Mathematically, if we denote a_unit_A as a expressed in frame A after normalization (a_unit_A has unit length), and b_unit_B as b expressed in frame B after normalization, the constraint is cos(θ_upper) ≤ a_unit_Aᵀ * R_AB * b_unit_B ≤ cos(θ_lower)

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

Public Member Functions

 AngleBetweenVectorsConstraint (const MultibodyPlant< double > *plant, const Frame< double > &frameA, const Eigen::Ref< const Eigen::Vector3d > &a_A, const Frame< double > &frameB, const Eigen::Ref< const Eigen::Vector3d > &b_B, double angle_lower, double angle_upper, systems::Context< double > *context)
 Constructs an AngleBetweenVectorsConstraint. More...
 
 AngleBetweenVectorsConstraint (const MultibodyPlant< AutoDiffXd > *plant, const Frame< AutoDiffXd > &frameA, const Eigen::Ref< const Eigen::Vector3d > &a_A, const Frame< AutoDiffXd > &frameB, const Eigen::Ref< const Eigen::Vector3d > &b_B, double angle_lower, double angle_upper, systems::Context< AutoDiffXd > *context)
 Overloaded constructor. More...
 
 ~AngleBetweenVectorsConstraint () override
 
Does not allow copy, move, or assignment
 AngleBetweenVectorsConstraint (const AngleBetweenVectorsConstraint &)=delete
 
AngleBetweenVectorsConstraintoperator= (const AngleBetweenVectorsConstraint &)=delete
 
 AngleBetweenVectorsConstraint (AngleBetweenVectorsConstraint &&)=delete
 
AngleBetweenVectorsConstraintoperator= (AngleBetweenVectorsConstraint &&)=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...
 
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 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 > &lower_bound, const Eigen::Ref< const Eigen::VectorXd > &upper_bound)
 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...
 
void set_num_outputs (int num_outputs)
 

Constructor & Destructor Documentation

◆ AngleBetweenVectorsConstraint() [1/4]

◆ AngleBetweenVectorsConstraint() [2/4]

◆ AngleBetweenVectorsConstraint() [3/4]

AngleBetweenVectorsConstraint ( const MultibodyPlant< double > *  plant,
const Frame< double > &  frameA,
const Eigen::Ref< const Eigen::Vector3d > &  a_A,
const Frame< double > &  frameB,
const Eigen::Ref< const Eigen::Vector3d > &  b_B,
double  angle_lower,
double  angle_upper,
systems::Context< double > *  context 
)

Constructs an AngleBetweenVectorsConstraint.

Parameters
plantThe MultibodyPlant on which the constraint is imposed. plant should be alive during the lifetime of this constraint.
frameAThe Frame object for frame A.
a_AThe vector a fixed to frame A, expressed in frame A.
frameBThe Frame object for frame B.
b_BThe vector b fixed to frame B, expressed in frameB.
angle_lowerThe lower bound on the angle between a and b. It is denoted as θ_lower in the class documentation.
angle_upperThe upper bound on the angle between a and b. it is denoted as θ_upper in the class documentation.
contextThe Context that has been allocated for this plant. We will update the context when evaluating the constraint. context should be alive during the lifetime of this constraint.
Precondition
frameA and frameB must belong to plant.
Exceptions
std::invalid_argumentif plant is nullptr.
std::invalid_argumentif a_A is close to zero.
std::invalid_argumentif b_B is close to zero.
std::invalid_argumentif angle_lower is negative.
std::invalid_argumentif angle_upper ∉ [angle_lower, π].
std::invalid_argumentif context is nullptr.

◆ AngleBetweenVectorsConstraint() [4/4]

AngleBetweenVectorsConstraint ( const MultibodyPlant< AutoDiffXd > *  plant,
const Frame< AutoDiffXd > &  frameA,
const Eigen::Ref< const Eigen::Vector3d > &  a_A,
const Frame< AutoDiffXd > &  frameB,
const Eigen::Ref< const Eigen::Vector3d > &  b_B,
double  angle_lower,
double  angle_upper,
systems::Context< AutoDiffXd > *  context 
)

Overloaded constructor.

Use MultibodyPlant<AutoDiffXd> instead of MultibodyPlant<double>.

◆ ~AngleBetweenVectorsConstraint()

Member Function Documentation

◆ operator=() [1/2]

◆ operator=() [2/2]


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