Ejemplo n.º 1
0
void inverseKinBackend(
    RigidBodyTree* model, const int nT,
    const double* t, const MatrixBase<DerivedA>& q_seed,
    const MatrixBase<DerivedB>& q_nom, const int num_constraints,
    RigidBodyConstraint** const constraint_array,
    const IKoptions& ikoptions, MatrixBase<DerivedC>* q_sol,
    int* info, std::vector<std::string>* infeasible_constraint) {

  // Validate some basic parameters of the input.
  if (q_seed.rows() != model->number_of_positions() || q_seed.cols() != nT ||
      q_nom.rows() != model->number_of_positions() || q_nom.cols() != nT) {
    throw std::runtime_error(
        "Drake::inverseKinBackend: q_seed and q_nom must be of size "
        "nq x nT");
  }

  KinematicsCacheHelper<double> kin_helper(model->bodies);

  // TODO(sam.creasey) I really don't like rebuilding the
  // OptimizationProblem for every timestep, but it's not possible to
  // enable/disable (or even remove) a constraint from an
  // OptimizationProblem between calls to Solve() currently, so
  // there's not actually another way.
  for (int t_index = 0; t_index < nT; t_index++) {
    OptimizationProblem prog;
    SetIKSolverOptions(ikoptions, &prog);

    DecisionVariableView vars =
        prog.AddContinuousVariables(model->number_of_positions());

    MatrixXd Q;
    ikoptions.getQ(Q);
    auto objective = std::make_shared<InverseKinObjective>(model, Q);
    prog.AddCost(objective, {vars});

    for (int i = 0; i < num_constraints; i++) {
      RigidBodyConstraint* constraint = constraint_array[i];
      const int constraint_category = constraint->getCategory();
      if (constraint_category ==
          RigidBodyConstraint::SingleTimeKinematicConstraintCategory) {
        SingleTimeKinematicConstraint* stc =
            static_cast<SingleTimeKinematicConstraint*>(constraint);
        if (!stc->isTimeValid(&t[t_index])) { continue; }
        auto wrapper = std::make_shared<SingleTimeKinematicConstraintWrapper>(
            stc, &kin_helper);
        prog.AddConstraint(wrapper, {vars});
      } else if (constraint_category ==
                 RigidBodyConstraint::PostureConstraintCategory) {
        PostureConstraint* pc = static_cast<PostureConstraint*>(constraint);
        if (!pc->isTimeValid(&t[t_index])) { continue; }
        VectorXd lb;
        VectorXd ub;
        pc->bounds(&t[t_index], lb, ub);
        prog.AddBoundingBoxConstraint(lb, ub, {vars});
      } else if (
          constraint_category ==
          RigidBodyConstraint::SingleTimeLinearPostureConstraintCategory) {
        AddSingleTimeLinearPostureConstraint(
            &t[t_index], constraint, model->number_of_positions(),
            vars, &prog);
      } else if (constraint_category ==
                 RigidBodyConstraint::QuasiStaticConstraintCategory) {
        AddQuasiStaticConstraint(&t[t_index], constraint, &kin_helper,
                                 vars, &prog);
      } else if (constraint_category ==
                 RigidBodyConstraint::MultipleTimeKinematicConstraintCategory) {
        throw std::runtime_error(
            "MultipleTimeKinematicConstraint is not supported"
            " in pointwise mode.");
      } else if (
          constraint_category ==
          RigidBodyConstraint::MultipleTimeLinearPostureConstraintCategory) {
        throw std::runtime_error(
            "MultipleTimeLinearPostureConstraint is not supported"
            " in pointwise mode.");
      }
    }

    // Add a bounding box constraint from the model.
    prog.AddBoundingBoxConstraint(
        model->joint_limit_min, model->joint_limit_max,
        {vars});

    // TODO(sam.creasey) would this be faster if we stored the view
    // instead of copying into a VectorXd?
    objective->set_q_nom(q_nom.col(t_index));
    if (!ikoptions.getSequentialSeedFlag() || (t_index == 0)) {
      prog.SetInitialGuess(vars, q_seed.col(t_index));
    } else {
      prog.SetInitialGuess(vars, q_sol->col(t_index - 1));
    }

    SolutionResult result = prog.Solve();
    prog.PrintSolution();
    q_sol->col(t_index) = vars.value();
    info[t_index] = GetIKSolverInfo(prog, result);
  }
}