示例#1
0
int contactConstraintsBV(
    const RigidBodyTree<double>& r,
    const KinematicsCache<double>& cache, int nc,
    std::vector<double> support_mus,
    // TODO(#2274) Fix NOLINTNEXTLINE(runtime/references).
    drake::eigen_aligned_std_vector<SupportStateElement>& supp, MatrixXd& B,
    // TODO(#2274) Fix NOLINTNEXTLINE(runtime/references).
    MatrixXd& JB, MatrixXd& Jp, VectorXd& Jpdotv, MatrixXd& normals) {
  int j, k = 0, nq = r.get_num_positions();

  B.resize(3, nc * 2 * m_surface_tangents);
  JB.resize(nq, nc * 2 * m_surface_tangents);
  Jp.resize(3 * nc, nq);
  Jpdotv.resize(3 * nc);
  normals.resize(3, nc);

  Vector3d contact_pos, pos, normal;
  MatrixXd J(3, nq);
  Matrix<double, 3, m_surface_tangents> d;

  for (auto iter = supp.begin(); iter != supp.end(); iter++) {
    double mu = support_mus[iter - supp.begin()];
    double norm = sqrt(1 + mu * mu);  // because normals and ds are orthogonal,
                                      // the norm has a simple form
    if (nc > 0) {
      for (auto pt_iter = iter->contact_pts.begin();
           pt_iter != iter->contact_pts.end(); pt_iter++) {
        contact_pos = r.transformPoints(cache, *pt_iter, iter->body_idx, 0);
        J = r.transformPointsJacobian(cache, *pt_iter, iter->body_idx, 0, true);

        normal = iter->support_surface.head(3);
        surfaceTangents(normal, d);
        for (j = 0; j < m_surface_tangents; j++) {
          B.col(2 * k * m_surface_tangents + j) =
              (normal + mu * d.col(j)) / norm;
          B.col((2 * k + 1) * m_surface_tangents + j) =
              (normal - mu * d.col(j)) / norm;

          JB.col(2 * k * m_surface_tangents + j) =
              J.transpose() * B.col(2 * k * m_surface_tangents + j);
          JB.col((2 * k + 1) * m_surface_tangents + j) =
              J.transpose() * B.col((2 * k + 1) * m_surface_tangents + j);
        }

        // store away kin sols into Jp and Jpdotv
        // NOTE: I'm cheating and using a slightly different ordering of J and
        // Jdot here
        Jp.block(3 * k, 0, 3, nq) = J;
        Vector3d pt = (*pt_iter).head(3);
        Jpdotv.block(3 * k, 0, 3, 1) =
            r.transformPointsJacobianDotTimesV(cache, pt, iter->body_idx, 0);
        normals.col(k) = normal;

        k++;
      }
    }
  }

  return k;
}
Matrix<Scalar, Dynamic, DerivedPoints::ColsAtCompileTime> forwardKinTemp(const RigidBodyTree& tree,
    const KinematicsCache<Scalar> &cache, const MatrixBase<DerivedPoints> &points, int current_body_or_frame_ind, int new_body_or_frame_ind, int rotation_type) {

  Matrix<Scalar, Dynamic, DerivedPoints::ColsAtCompileTime> ret(3 + rotationRepresentationSize(rotation_type), points.cols());
  ret.template topRows<3>() = tree.transformPoints(cache, points, current_body_or_frame_ind, new_body_or_frame_ind);
  if (rotation_type == 1) {
    ret.template bottomRows<3>().colwise() = tree.relativeRollPitchYaw(cache, current_body_or_frame_ind, new_body_or_frame_ind);
  }
  else if (rotation_type == 2) {
    ret.template bottomRows<4>().colwise() = tree.relativeQuaternion(cache, current_body_or_frame_ind, new_body_or_frame_ind);
  }
  return ret;
};
示例#3
0
int main(int argc, char* argv[]) {
  if (argc < 2) {
    cerr << "Usage: urdfKinTest urdf_filename" << endl;
    exit(-1);
  }
  RigidBodyTree* model = new RigidBodyTree(argv[1]);
  cout << "=======" << endl;

  // run kinematics with second derivatives 100 times
  Eigen::VectorXd q = model->getZeroConfiguration();
  Eigen::VectorXd v = Eigen::VectorXd::Zero(model->num_velocities);
  int i;

  if (argc >= 2 + model->num_positions) {
    for (i = 0; i < model->num_positions; i++)
      sscanf(argv[2 + i], "%lf", &q(i));
  }

  // for (i=0; i<model->num_dof; i++)
  // 	 q(i)=(double)rand() / RAND_MAX;
  KinematicsCache<double> cache = model->doKinematics(q, v);
  //  }

  //  const Vector4d zero(0,0,0,1);
  Eigen::Vector3d zero = Eigen::Vector3d::Zero();
  Eigen::Matrix<double, 6, 1> pt;

  for (i = 0; i < model->bodies.size(); i++) {
    //    model->forwardKin(i,zero,1,pt);
    auto pt = model->transformPoints(cache, zero, i, 0);
    auto rpy = model->relativeRollPitchYaw(cache, i, 0);
    Eigen::Matrix<double, 6, 1> x;
    x << pt, rpy;
    //    cout << i << ": forward kin: " << model->bodies[i].linkname << " is at
    //    " << pt.transpose() << endl;
    cout << model->bodies[i]->linkname << " ";
    cout << x.transpose() << endl;
    //    for (int j=0; j<pt.size(); j++)
    //    	cout << pt(j) << " ";
  }

  auto phi = model->positionConstraints<double>(cache);
  cout << "phi = " << phi.transpose() << endl;

  delete model;
  return 0;
}
示例#4
0
int contactPhi(const RigidBodyTree &r, const KinematicsCache<double> &cache,
               SupportStateElement &supp, VectorXd &phi) {
  int nc = static_cast<int>(supp.contact_pts.size());
  phi.resize(nc);

  if (nc < 1) return nc;

  int i = 0;
  for (auto pt_iter = supp.contact_pts.begin();
       pt_iter != supp.contact_pts.end(); pt_iter++) {
    Vector3d contact_pos = r.transformPoints(cache, *pt_iter, supp.body_idx, 0);
    phi(i) = supp.support_surface.head<3>().dot(contact_pos) +
             supp.support_surface(3);
    i++;
  }
  return nc;
}
示例#5
0
MatrixXd individualSupportCOPs(
    const RigidBodyTree &r, const KinematicsCache<double> &cache,
    const std::vector<SupportStateElement,
                      Eigen::aligned_allocator<SupportStateElement>> &
        active_supports,
    const MatrixXd &normals, const MatrixXd &B, const VectorXd &beta) {
  const int n_basis_vectors_per_contact =
      static_cast<int>(B.cols() / normals.cols());
  const int n = static_cast<int>(active_supports.size());

  int normals_start = 0;
  int beta_start = 0;

  MatrixXd individual_cops(3, n);
  individual_cops.fill(std::numeric_limits<double>::quiet_NaN());

  for (size_t j = 0; j < active_supports.size(); j++) {
    auto active_support = active_supports[j];
    auto contact_pts = active_support.contact_pts;

    int ncj = static_cast<int>(contact_pts.size());
    int active_support_length = n_basis_vectors_per_contact * ncj;
    auto normalsj = normals.middleCols(normals_start, ncj);
    Vector3d normal = normalsj.col(0);
    bool normals_identical =
        (normalsj.colwise().operator-(normal)).squaredNorm() < 1e-15;

    if (normals_identical) {  // otherwise computing a COP doesn't make sense
      const auto &Bj = B.middleCols(beta_start, active_support_length);
      const auto &betaj = beta.segment(beta_start, active_support_length);

      const auto &contact_positions =
          r.bodies[active_support.body_idx]->contact_pts;
      Vector3d force = Vector3d::Zero();
      Vector3d torque = Vector3d::Zero();

      for (size_t k = 0; k < contact_pts.size(); k++) {
        // for (auto k = contact_pts.begin(); k!= contact_pts.end(); k++) {
        const auto &Bblock = Bj.middleCols(k * n_basis_vectors_per_contact,
                                           n_basis_vectors_per_contact);
        const auto &betablock = betaj.segment(k * n_basis_vectors_per_contact,
                                              n_basis_vectors_per_contact);
        Vector3d point_force = Bblock * betablock;
        force += point_force;
        Vector3d contact_pt = contact_pts[k].head(3);
        auto torquejk = contact_pt.cross(point_force);
        torque += torquejk;
      }

      Vector3d point_on_contact_plane = contact_positions.col(0);
      std::pair<Vector3d, double> cop_and_normal_torque =
          resolveCenterOfPressure(torque, force, normal,
                                  point_on_contact_plane);
      Vector3d cop_world = r.transformPoints(cache, cop_and_normal_torque.first,
                                             active_support.body_idx, 0);
      individual_cops.col(j) = cop_world;
    }

    normals_start += ncj;
    beta_start += active_support_length;
  }
  return individual_cops;
}