|
Drake
|
|
Drake
|
Given the set of contacts between the fingertips and the brick, impose the static equilibrium as a nonlinear constraint, that the total force/torque applied on the brick is 0.
The decision variables are (q, f_Cb_B) where q is the generalized position, and f_Cb_B are the contact force (y, z) component applied to the point Cb on the brick, expressed in the brick frame B. The constraint are
0 = R_BW * m * g_W + ∑ᵢ f_Cbi_B 0 = ∑ᵢp_Cbi_B.cross(f_Cbi_B)
Notice that since the gripper/brick system is planar, the first equation is only on the (y, z) component of the total force, and the second equation is only on the x component of the torque.
The constraint evaluates the right-hand side of the two equations above.
#include <drake/examples/planar_gripper/brick_static_equilibrium_constraint.h>
Public Member Functions | |
| BrickStaticEquilibriumNonlinearConstraint (const GripperBrickHelper< double > &gripper_brick_system, std::vector< std::pair< Finger, BrickFace >> finger_face_contacts, systems::Context< double > *plant_mutable_context) | |
 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... | |
| EvaluatorBase (const EvaluatorBase &)=delete | |
| EvaluatorBase & | operator= (const EvaluatorBase &)=delete |
| EvaluatorBase (EvaluatorBase &&)=delete | |
| EvaluatorBase & | operator= (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) |
| BrickStaticEquilibriumNonlinearConstraint | ( | const GripperBrickHelper< double > & | gripper_brick_system, |
| std::vector< std::pair< Finger, BrickFace >> | finger_face_contacts, | ||
| systems::Context< double > * | plant_mutable_context | ||
| ) |