Classes | Functions
Constraints

Some robots can be subject to constraints. More...

Classes

class  hpp::core::ConfigProjector
 Implicit non-linear constraint. More...
 
class  hpp::core::ConstraintSet
 Set of constraints applicable to a robot configuration. More...
 
class  hpp::core::Constraint
 Constraint applicable to a robot configuration. More...
 

Functions

std::ostream & hpp::core::operator<< (std::ostream &os, const Constraint &constraint)
 

Detailed Description

Some robots can be subject to constraints.

are examples of such constraints. These constraints can be defined implicitely by an equation the left hand side of which is a differentiable function of the robot configuration.

Classes of this module enable users to define such constraints by deriving class Constraint and by storing instances in ConstraintSet.

ConfigProjector defines implicit constraints by equalities and/or inequalities between a differentiable function and a constant vector.

LockedJoint set the position of one joint to a fixed value.

Each ConstraintSet may contain at most one ConfigProjector. LockedJoint instances added to a ConstraintSet are in fact stored by the ConfigProjector of the ConstraintSet if any. The rationale is that the computations that solve numerical constraints are optimized by solving only for non locked degrees of freedom.

Below is a diagram of the classes that implement constraints with the description of some methods to help advanced user to understand how those classes interact between each other.

Constraint

ConstraintSet
addToSet (set):
  set.push_back (self)

addLockedJoint (lockedDof):
  pass		 addToSet (set):
  for c in constraints_:
    c.addToSet (set)

addLockedJoint (ld):
  for c in constraints_:
    c.addLockedJoint (ld)

addConstraint (c):
  c.addToSet (self)

ConfigProjector

addToSet (set):
  if set.configProjector_:
    throw
  if set.lockedDof_:
    throw
  set.removeConfigProjector ()
  set.configProjector_ = self
  Constraint::addToSet (set)

LockedJoint

addToSet (set):
  set.lockedJoint_ = true
  set.addLockedJoint (self)

Function Documentation

◆ operator<<()

std::ostream& hpp::core::operator<< ( std::ostream &  os,
const Constraint &  constraint 
)
inline

Referenced by hpp::core::Path::impl_velocityBound(), hpp::core::Roadmap::push_node(), and hpp::core::Node::~Node().