spline_acc_constraint.cc

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#include <towr/constraints/spline_acc_constraint.h>

namespace towr {

SplineAccConstraint::SplineAccConstraint (const NodeSpline::Ptr& spline,
                                          std::string node_variable_name)
    :ConstraintSet(kSpecifyLater, "SplineAcc-Constraint-" + node_variable_name)
{
  spline_ = spline;
  node_variables_id_ = node_variable_name;

  n_dim_       = spline->GetPoint(0.0).p().rows();
  n_junctions_ = spline->GetPolynomialCount() - 1;
  T_           = spline->GetPolyDurations();

  SetRows(n_dim_*n_junctions_);
}

Eigen::VectorXd
SplineAccConstraint::GetValues () const
{
  VectorXd g(GetRows());

  for (int j=0; j<n_junctions_; ++j) {
    int p_prev = j; // id of previous polynomial
    VectorXd acc_prev = spline_->GetPoint(p_prev, T_.at(p_prev)).a();

    int p_next = j+1;
    VectorXd acc_next = spline_->GetPoint(p_next, 0.0).a();

    g.segment(j*n_dim_, n_dim_) = acc_prev - acc_next;
  }

  return g;
}

void
SplineAccConstraint::FillJacobianBlock (std::string var_set, Jacobian& jac) const
{
  if (var_set == node_variables_id_) {
    for (int j=0; j<n_junctions_; ++j) {
      int p_prev = j; // id of previous polynomial
      Jacobian acc_prev = spline_->GetJacobianWrtNodes(p_prev, T_.at(p_prev), kAcc);

      int p_next = j+1;
      Jacobian acc_next = spline_->GetJacobianWrtNodes(p_next, 0.0, kAcc);

      jac.middleRows(j*n_dim_, n_dim_) = acc_prev - acc_next;
    }
  }
}

SplineAccConstraint::VecBound
SplineAccConstraint::GetBounds () const
{
  return VecBound(GetRows(), ifopt::BoundZero);
}

} /* namespace xpp */