nlp_factory.cc

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#include <towr/nlp_factory.h>

#include <towr/variables/variable_names.h>
#include <towr/variables/base_nodes.h>
#include <towr/variables/phase_durations.h>

#include <towr/constraints/base_motion_constraint.h>
#include <towr/constraints/dynamic_constraint.h>
#include <towr/constraints/force_constraint.h>
#include <towr/constraints/range_of_motion_constraint.h>
#include <towr/constraints/swing_constraint.h>
#include <towr/constraints/terrain_constraint.h>
#include <towr/constraints/total_duration_constraint.h>
#include <towr/constraints/spline_acc_constraint.h>

#include <towr/costs/node_cost.h>

namespace towr {


NlpFactory::VariablePtrVec
NlpFactory::GetVariableSets ()
{
  VariablePtrVec vars;

  auto base_motion = MakeBaseVariables();
  vars.insert(vars.end(), base_motion.begin(), base_motion.end());

  auto ee_motion = MakeEndeffectorVariables();
  vars.insert(vars.end(), ee_motion.begin(), ee_motion.end());

  auto ee_force = MakeForceVariables();
  vars.insert(vars.end(), ee_force.begin(), ee_force.end());

  auto contact_schedule = MakeContactScheduleVariables();
  if (params_.OptimizeTimings()) {
    vars.insert(vars.end(), contact_schedule.begin(), contact_schedule.end());
  }

  // stores these readily constructed spline, independent of whether the
  // nodes and durations these depend on are optimized over
  spline_holder_ = SplineHolder(base_motion.at(0), // linear
                                base_motion.at(1), // angular
                                params_.GetBasePolyDurations(),
                                ee_motion,
                                ee_force,
                                contact_schedule,
                                params_.OptimizeTimings());
  return vars;
}

std::vector<Nodes::Ptr>
NlpFactory::MakeBaseVariables () const
{
  std::vector<Nodes::Ptr> vars;

  int n_nodes = params_.GetBasePolyDurations().size() + 1;

  auto spline_lin = std::make_shared<BaseNodes>(n_nodes, id::base_lin_nodes);
  spline_lin->InitializeNodesTowardsGoal(initial_base_.lin.p(), final_base_.lin.p(), params_.t_total_);
  spline_lin->AddStartBound(kPos, {X,Y,Z}, initial_base_.lin.p());
  spline_lin->AddStartBound(kVel, {X,Y,Z}, initial_base_.lin.v());
  spline_lin->AddFinalBound(kPos, {X,Y}  , final_base_.lin.p());
  spline_lin->AddFinalBound(kVel, {X,Y,Z}, final_base_.lin.v());
  vars.push_back(spline_lin);

  auto spline_ang = std::make_shared<BaseNodes>(n_nodes,  id::base_ang_nodes);
  spline_ang->InitializeNodesTowardsGoal(initial_base_.ang.p(), final_base_.ang.p(), params_.t_total_);
  spline_ang->AddStartBound(kPos, {X,Y,Z}, initial_base_.ang.p());
  spline_ang->AddStartBound(kVel, {X,Y,Z}, initial_base_.ang.v());
  spline_ang->AddFinalBound(kPos,     {Z}, final_base_.ang.p());
  spline_ang->AddFinalBound(kVel, {X,Y,Z}, final_base_.ang.v());
  vars.push_back(spline_ang);

  return vars;
}

std::vector<PhaseNodes::Ptr>
NlpFactory::MakeEndeffectorVariables () const
{
  std::vector<PhaseNodes::Ptr> vars;

  // Endeffector Motions
  double T = params_.t_total_;
  for (int ee=0; ee<params_.GetEECount(); ee++) {

    auto nodes = std::make_shared<PhaseNodes>(params_.GetPhaseCount(ee),
                                              params_.ee_in_contact_at_start_.at(ee),
                                              id::EEMotionNodes(ee),
                                              params_.ee_polynomials_per_swing_phase_,
                                              PhaseNodes::Motion);

    double yaw = final_base_.ang.p().z();

    // smell adapt to desired yaw state
//    Eigen::Matrix3d w_R_b = GetQuaternionFromEulerZYX(yaw, 0.0, 0.0).toRotationMatrix();
    Eigen::Matrix3d w_R_b; w_R_b.setIdentity();

    Vector3d final_ee_pos_W = final_base_.lin.p() + w_R_b*model_.kinematic_model_->GetNominalStanceInBase().at(ee);



    nodes->InitializeNodesTowardsGoal(initial_ee_W_.at(ee), final_ee_pos_W, T);

    // actually initial Z position should be constrained as well...-.-
    nodes->AddStartBound(kPos, {X,Y}, initial_ee_W_.at(ee));

    // fix final endeffector position
//    bool step_taken = nodes->GetNodes().size() > 2;
//    if (step_taken) // otherwise overwrites start bound
//      nodes->AddFinalBound(kPos, {X,Y}, final_ee_pos_W);

    vars.push_back(nodes);
  }


  return vars;
}

std::vector<PhaseNodes::Ptr>
NlpFactory::MakeForceVariables () const
{
  std::vector<PhaseNodes::Ptr> vars;

  double T = params_.t_total_;
  for (int ee=0; ee<params_.GetEECount(); ee++) {

    auto nodes = std::make_shared<PhaseNodes>(params_.GetPhaseCount(ee),
                                              params_.ee_in_contact_at_start_.at(ee),
                                              id::EEForceNodes(ee),
                                              params_.force_polynomials_per_stance_phase_,
                                              PhaseNodes::Force);

    // initialize with mass of robot distributed equally on all legs
    double m = model_.dynamic_model_->m();
    double g = model_.dynamic_model_->g();


    Vector3d f_stance(0.0, 0.0, m*g/params_.GetEECount());
    nodes->InitializeNodesTowardsGoal(f_stance, f_stance, T);
    vars.push_back(nodes);
  }

  return vars;
}

std::vector<PhaseDurations::Ptr>
NlpFactory::MakeContactScheduleVariables () const
{
  std::vector<PhaseDurations::Ptr> vars;

  for (int ee=0; ee<params_.GetEECount(); ee++) {

    auto var = std::make_shared<PhaseDurations>(ee,
                                                params_.ee_phase_durations_.at(ee),
                                                params_.ee_in_contact_at_start_.at(ee),
                                                params_.min_phase_duration_,
                                                params_.max_phase_duration_);
    vars.push_back(var);
  }

  return vars;
}

NlpFactory::ContraintPtrVec
NlpFactory::GetConstraints() const
{
  ContraintPtrVec constraints;
  for (ConstraintName name : params_.constraints_)
    for (auto c : GetConstraint(name))
      constraints.push_back(c);

  return constraints;
}

NlpFactory::ContraintPtrVec
NlpFactory::GetConstraint (ConstraintName name) const
{
  switch (name) {
    case Dynamic:        return MakeDynamicConstraint();
    case EndeffectorRom: return MakeRangeOfMotionBoxConstraint();
    case BaseRom:        return MakeBaseRangeOfMotionConstraint();
    case TotalTime:      return MakeTotalTimeConstraint();
    case Terrain:        return MakeTerrainConstraint();
    case Force:          return MakeForceConstraint();
    case Swing:          return MakeSwingConstraint();
    case BaseAcc:        return MakeBaseAccConstraint();
    default: throw std::runtime_error("constraint not defined!");
  }
}


NlpFactory::ContraintPtrVec
NlpFactory::MakeBaseRangeOfMotionConstraint () const
{
  return {std::make_shared<BaseMotionConstraint>(params_, spline_holder_)};
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeDynamicConstraint() const
{
  auto constraint = std::make_shared<DynamicConstraint>(model_.dynamic_model_,
                                                        params_,
                                                        spline_holder_);
  return {constraint};
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeRangeOfMotionBoxConstraint () const
{
  ContraintPtrVec c;

  for (int ee=0; ee<params_.GetEECount(); ee++) {
    auto rom_constraints = std::make_shared<RangeOfMotionConstraint>(model_.kinematic_model_,
                                                              params_,
                                                              ee,
                                                              spline_holder_);
    c.push_back(rom_constraints);
  }

  return c;
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeTotalTimeConstraint () const
{
  ContraintPtrVec c;
  double T = params_.t_total_;

  for (int ee=0; ee<params_.GetEECount(); ee++) {
    auto duration_constraint = std::make_shared<TotalDurationConstraint>(T, ee);
    c.push_back(duration_constraint);
  }

  return c;
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeTerrainConstraint () const
{
  ContraintPtrVec constraints;

  for (int ee=0; ee<params_.GetEECount(); ee++) {
    auto c = std::make_shared<TerrainConstraint>(terrain_, id::EEMotionNodes(ee));
    constraints.push_back(c);
  }

  return constraints;
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeForceConstraint () const
{
  ContraintPtrVec constraints;

  for (int ee=0; ee<params_.GetEECount(); ee++) {
    auto c = std::make_shared<ForceConstraint>(terrain_,
                                               params_.force_limit_in_norm_,
                                               ee);
    constraints.push_back(c);
  }

  return constraints;
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeSwingConstraint () const
{
  ContraintPtrVec constraints;

  for (int ee=0; ee<params_.GetEECount(); ee++) {
    auto swing = std::make_shared<SwingConstraint>(id::EEMotionNodes(ee));
    constraints.push_back(swing);
  }

  return constraints;
}

NlpFactory::ContraintPtrVec
NlpFactory::MakeBaseAccConstraint () const
{
  ContraintPtrVec constraints;

  constraints.push_back(std::make_shared<SplineAccConstraint>
                        (spline_holder_.base_linear_, id::base_lin_nodes));

  constraints.push_back(std::make_shared<SplineAccConstraint>
                        (spline_holder_.base_angular_, id::base_ang_nodes));

  return constraints;
}

NlpFactory::ContraintPtrVec
NlpFactory::GetCosts() const
{
  ContraintPtrVec costs;
  for (const auto& pair : params_.costs_)
    for (auto c : GetCost(pair.first, pair.second))
      costs.push_back(c);

  return costs;
}

NlpFactory::CostPtrVec
NlpFactory::GetCost(const CostName& name, double weight) const
{
  switch (name) {
    case ForcesCostID:       return MakeForcesCost(weight);
    default: throw std::runtime_error("cost not defined!");
  }
}

NlpFactory::CostPtrVec
NlpFactory::MakeForcesCost(double weight) const
{
  CostPtrVec cost;

  for (int ee=0; ee<params_.GetEECount(); ee++)
    cost.push_back(std::make_shared<NodeCost>(id::EEForceNodes(ee), kPos, Z));

  return cost;
}

} /* namespace towr */