planner.h

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/*
 * Copyright (c) 2018, The Regents of the University of California (Regents).
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 *    2. Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
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 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * Please contact the author(s) of this library if you have any questions.
 * Authors: David Fridovich-Keil   ( dfk@eecs.berkeley.edu )
 */

//
// Base class for all planners. Planners are templated on state and dynamics
// types **of the planner** NOT **of the tracker,** as well as the tracking
// error bound type and environment. Planners take in start and goal states, and
// start time, and output a trajectory of planner states.
//
// Templated on state (S), environment (E), dynamics (D), dynamics service (SD),
// bound (B), and bound service (SB).
//

#ifndef FASTRACK_PLANNING_PLANNER_H
#define FASTRACK_PLANNING_PLANNER_H

#include <fastrack/environment/environment.h>
#include <fastrack/trajectory/trajectory.h>
#include <fastrack/utils/types.h>

#include <fastrack_srvs/Replan.h>
#include <fastrack_srvs/ReplanRequest.h>
#include <fastrack_srvs/ReplanResponse.h>
#include <fastrack_msgs/Trajectory.h>

#include <ros/ros.h>
#include <visualization_msgs/Marker.h>

namespace fastrack {
namespace planning {

using environment::Environment;
using trajectory::Trajectory;

template<typename S, typename E,
         typename D, typename SD, typename B, typename SB>
class Planner {
public:
  virtual ~Planner() {}

  // Initialize from a ROS NodeHandle.
  bool Initialize(const ros::NodeHandle& n);

protected:
  explicit Planner()
    : initialized_(false) {}

  // Load parameters and register callbacks. These may be overridden
  // by derived classes if needed (they should still call these functions
  // via Planner::LoadParameters and Planner::RegisterCallbacks).
  virtual bool LoadParameters(const ros::NodeHandle& n);
  virtual bool RegisterCallbacks(const ros::NodeHandle& n);

  // Callback to handle replanning requests.
  inline bool ReplanServer(
    fastrack_srvs::ReplanRequest& req, fastrack_srvs::ReplanResponse& res) {
    // Unpack start/stop states.
    const S start(req.req.start);
    const S goal(req.req.goal);

    // Plan.
    const Trajectory<S> traj = Plan(start, goal, req.req.start_time);

    // Return whether or not planning was successful.
    res.traj = traj.ToRos();
    return traj.Size() > 0;
  }

  // Plan a trajectory from the given start to goal states starting
  // at the given time.
  virtual Trajectory<S> Plan(
    const S& start, const S& goal, double start_time=0.0) const = 0;

  // Keep a copy of the dynamics, tracking bound, and environment.
  D dynamics_;
  B bound_;
  E env_;

  // Max amount of time for planning to run each time.
  double max_runtime_;

  // State space bounds.
  std::vector<double> state_upper_;
  std::vector<double> state_lower_;

  // Replanning server.
  ros::ServiceServer replan_srv_;
  std::string replan_srv_name_;

  // Services for loading dynamics and bound.
  ros::ServiceClient dynamics_srv_;
  ros::ServiceClient bound_srv_;

  std::string dynamics_srv_name_;
  std::string bound_srv_name_;

  // Naming and initialization.
  std::string name_;
  bool initialized_;
}; //\class Planner

// ----------------------------- IMPLEMENTATION ----------------------------- //

// Initialize from a ROS NodeHandle.
template<typename S, typename E,
         typename D, typename SD, typename B, typename SB>
bool Planner<S, E, D, SD, B, SB>::Initialize(const ros::NodeHandle& n) {
  name_ = ros::names::append(n.getNamespace(), "Planner");

  if (!LoadParameters(n)) {
    ROS_ERROR("%s: Failed to load parameters.", name_.c_str());
    return false;
  }

  if (!RegisterCallbacks(n)) {
    ROS_ERROR("%s: Failed to register callbacks.", name_.c_str());
    return false;
  }

  // Initialize environment.
  if (!env_.Initialize(n)) {
    ROS_ERROR("%s: Failed to initialize environment.", name_.c_str());
    return false;
  }

  // Set bound by calling service provided by tracker.
  if (!bound_srv_) {
    ROS_ERROR("%s: Bound server was disconnected.", name_.c_str());
    return false;
  }

  SB b;
  if (!bound_srv_.call(b)) {
    ROS_ERROR("%s: Bound server error.", name_.c_str());
    return false;
  }

  bound_.FromRos(b.response);

  // Set dynamics by calling service provided by tracker.
  if (!dynamics_srv_) {
    ROS_ERROR("%s: Dynamics server was disconnected.", name_.c_str());
    return false;
  }

  SD d;
  if (!dynamics_srv_.call(d)) {
    ROS_ERROR("%s: Dynamics server error.", name_.c_str());
    return false;
  }

  dynamics_.FromRos(d.response);

  // Set configuration space bounds.
  S::SetBounds(state_lower_, state_upper_);

  initialized_ = true;
  return true;
}

// Load parameters.
template<typename S, typename E,
         typename D, typename SD, typename B, typename SB>
bool Planner<S, E, D, SD, B, SB>::LoadParameters(const ros::NodeHandle& n) {
  ros::NodeHandle nl(n);

  // Services.
  if (!nl.getParam("srv/replan", replan_srv_name_)) return false;
  if (!nl.getParam("srv/dynamics", dynamics_srv_name_)) return false;
  if (!nl.getParam("srv/bound", bound_srv_name_)) return false;

  // Max runtime per call.
  if (!nl.getParam("max_runtime", max_runtime_)) return false;

  // State space bounds.
  if (!nl.getParam("state/lower", state_lower_)) return false;
  if (!nl.getParam("state/upper", state_upper_)) return false;

  return true;
}

// Register callbacks.
template<typename S, typename E,
         typename D, typename SD, typename B, typename SB>
bool Planner<S, E, D, SD, B, SB>::RegisterCallbacks(const ros::NodeHandle& n) {
  ros::NodeHandle nl(n);

  // Services.
  replan_srv_ = nl.advertiseService(replan_srv_name_.c_str(),
    &Planner<S, E, D, SD, B, SB>::ReplanServer, this);

  ros::service::waitForService(dynamics_srv_name_);
  dynamics_srv_ = nl.serviceClient<SD>(dynamics_srv_name_.c_str(), true);

  ros::service::waitForService(bound_srv_name_);
  bound_srv_ = nl.serviceClient<SB>(bound_srv_name_.c_str(), true);

  return true;
}

} //\namespace planning
} //\namespace fastrack

#endif