Public Member Functions | Private Attributes
towr::ForceConstraint Class Reference

Ensures foot force that is unilateral and inside friction cone. More...

#include <force_constraint.h>

List of all members.

Public Member Functions

void FillJacobianBlock (std::string var_set, Jacobian &) const override
 ForceConstraint (const HeightMap::Ptr &terrain, double force_limit_in_normal_direction, EE endeffector_id)
 Constructs a force contraint.
VecBound GetBounds () const override
VectorXd GetValues () const override
void InitVariableDependedQuantities (const VariablesPtr &x) override
virtual ~ForceConstraint ()

Private Attributes

EE ee_
 The endeffector force to be constrained.
NodesVariablesPhaseBased::Ptr ee_force_
 the current xyz foot forces.
NodesVariablesPhaseBased::Ptr ee_motion_
 the current xyz foot positions.
double fn_max_
 force limit in normal direction.
double mu_
 friction coeff between robot feet and terrain.
int n_constraints_per_node_
 number of constraint for each node.
std::vector< int > pure_stance_force_node_ids_
HeightMap::Ptr terrain_
 gradient information at every position (x,y).

Detailed Description

Ensures foot force that is unilateral and inside friction cone.

This class is responsible for constraining the endeffector xyz-forces to only push into the terrain and additionally stay inside the friction cone according to the current slope.

In order to keep the constraint linear and simple for the solver to solve, we approximate the friction cone by a 4-sided pyramid.

Attention: Constraint is enforced only at the spline nodes. In between violations of this constraint can occur.

Definition at line 55 of file force_constraint.h.

Constructor & Destructor Documentation

towr::ForceConstraint::ForceConstraint ( const HeightMap::Ptr &  terrain,
double  force_limit_in_normal_direction,
EE  endeffector_id 

Constructs a force contraint.

terrainThe gradient information of the terrain for friction cone.
force_limit_in_normal_directionMaximum pushing force [N].
endeffector_idWhich endeffector force should be constrained.

Definition at line 37 of file

Member Function Documentation

void towr::ForceConstraint::FillJacobianBlock ( std::string  var_set,
Jacobian &  jac 
) const [override]

Definition at line 108 of file

ForceConstraint::VecBound towr::ForceConstraint::GetBounds ( ) const [override]

Definition at line 92 of file

Eigen::VectorXd towr::ForceConstraint::GetValues ( ) const [override]

Definition at line 63 of file

void towr::ForceConstraint::InitVariableDependedQuantities ( const VariablesPtr &  x) [override]

Definition at line 51 of file

Member Data Documentation

The endeffector force to be constrained.

Definition at line 85 of file force_constraint.h.

NodesVariablesPhaseBased::Ptr towr::ForceConstraint::ee_force_ [private]

the current xyz foot forces.

Definition at line 78 of file force_constraint.h.

NodesVariablesPhaseBased::Ptr towr::ForceConstraint::ee_motion_ [private]

the current xyz foot positions.

Definition at line 79 of file force_constraint.h.

force limit in normal direction.

Definition at line 82 of file force_constraint.h.

double towr::ForceConstraint::mu_ [private]

friction coeff between robot feet and terrain.

Definition at line 83 of file force_constraint.h.

number of constraint for each node.

Definition at line 84 of file force_constraint.h.

The are those Hermite-nodes that shape the polynomial during the stance phases, while all the others are already set to zero force (swing)

Definition at line 91 of file force_constraint.h.

HeightMap::Ptr towr::ForceConstraint::terrain_ [private]

gradient information at every position (x,y).

Definition at line 81 of file force_constraint.h.

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

Author(s): Alexander W. Winkler
autogenerated on Mon Apr 15 2019 02:42:32