towr_ros_app.cc
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29 
32 
33 
34 namespace towr {
35 
42 class TowrRosApp : public TowrRosInterface {
43 public:
47  void SetTowrInitialState() override
48  {
49  auto nominal_stance_B = formulation_.model_.kinematic_model_->GetNominalStanceInBase();
50 
51  double z_ground = 0.0;
52  formulation_.initial_ee_W_ = nominal_stance_B;
53  std::for_each(formulation_.initial_ee_W_.begin(), formulation_.initial_ee_W_.end(),
54  [&](Vector3d& p){ p.z() = z_ground; } // feet at 0 height
55  );
56 
57  formulation_.initial_base_.lin.at(kPos).z() = - nominal_stance_B.front().z() + z_ground;
58  }
59 
63  Parameters GetTowrParameters(int n_ee, const TowrCommandMsg& msg) const override
64  {
65  Parameters params;
66 
67  // Instead of manually defining the initial durations for each foot and
68  // step, for convenience we use a GaitGenerator with some predefined gaits
69  // for a variety of robots (walk, trot, pace, ...).
70  auto gait_gen_ = GaitGenerator::MakeGaitGenerator(n_ee);
71  auto id_gait = static_cast<GaitGenerator::Combos>(msg.gait);
72  gait_gen_->SetCombo(id_gait);
73  for (int ee=0; ee<n_ee; ++ee) {
74  params.ee_phase_durations_.push_back(gait_gen_->GetPhaseDurations(msg.total_duration, ee));
75  params.ee_in_contact_at_start_.push_back(gait_gen_->IsInContactAtStart(ee));
76  }
77 
78  // Here you can also add other constraints or change parameters
79  // params.constraints_.push_back(Parameters::BaseRom);
80 
81  // increases optimization time, but sometimes helps find a solution for
82  // more difficult terrain.
83  if (msg.optimize_phase_durations)
84  params.OptimizePhaseDurations();
85 
86  return params;
87  }
88 
92  void SetIpoptParameters(const TowrCommandMsg& msg) override
93  {
94  // the HA-L solvers are alot faster, so consider installing and using
95  solver_->SetOption("linear_solver", "mumps"); // ma27, ma57
96 
97  // Analytically defining the derivatives in IFOPT as we do it, makes the
98  // problem a lot faster. However, if this becomes too difficult, we can also
99  // tell IPOPT to just approximate them using finite differences. However,
100  // this uses numerical derivatives for ALL constraints, there doesn't yet
101  // exist an option to turn on numerical derivatives for only some constraint
102  // sets.
103  solver_->SetOption("jacobian_approximation", "exact"); // finite difference-values
104 
105  // This is a great to test if the analytical derivatives implemented in are
106  // correct. Some derivatives that are correct are still flagged, showing a
107  // deviation of 10e-4, which is fine. What to watch out for is deviations > 10e-2.
108  // solver_->SetOption("derivative_test", "first-order");
109 
110  solver_->SetOption("max_cpu_time", 40.0);
111  solver_->SetOption("print_level", 5);
112 
113  if (msg.play_initialization)
114  solver_->SetOption("max_iter", 0);
115  else
116  solver_->SetOption("max_iter", 3000);
117  }
118 };
119 
120 } // namespace towr
121 
122 
123 int main(int argc, char *argv[])
124 {
125  ros::init(argc, argv, "my_towr_ros_app");
126  towr::TowrRosApp towr_app;
127  ros::spin();
128 
129  return 1;
130 }
Parameters GetTowrParameters(int n_ee, const TowrCommandMsg &msg) const override
Sets the parameters required to formulate the TOWR problem.
Definition: towr_ros_app.cc:63
towr_ros::TowrCommand TowrCommandMsg
const VectorXd at(Dx deriv) const
ROSCPP_DECL void init(int &argc, char **argv, const std::string &name, uint32_t options=0)
ifopt::IpoptSolver::Ptr solver_
NLP solver, could also use SNOPT.
ROSCPP_DECL void spin(Spinner &spinner)
int main(int argc, char *argv[])
void SetTowrInitialState() override
Sets the feet to nominal position on flat ground and base above.
Definition: towr_ros_app.cc:47
Base class to interface TOWR with a ROS GUI and RVIZ.
std::vector< VecTimes > ee_phase_durations_
void OptimizePhaseDurations()
An example application of using TOWR together with ROS.
Definition: towr_ros_app.cc:42
std::vector< bool > ee_in_contact_at_start_
static Ptr MakeGaitGenerator(int leg_count)
KinematicModel::Ptr kinematic_model_
void SetIpoptParameters(const TowrCommandMsg &msg) override
Sets the paramters for IPOPT.
Definition: towr_ros_app.cc:92
NlpFormulation formulation_
the default formulation, can be adapted


towr_ros
Author(s): Alexander W. Winkler
autogenerated on Fri Apr 2 2021 02:14:21