sbpl_lattice_planner.cpp

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* Author: Mike Phillips
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#include <sbpl_lattice_planner/sbpl_lattice_planner.h>
#include <pluginlib/class_list_macros.hpp>
#include <nav_msgs/Path.h>
#include <sbpl_lattice_planner/SBPLLatticePlannerStats.h>

#include <costmap_2d/inflation_layer.h>
#include <tf2/LinearMath/Quaternion.h>

using namespace std;
using namespace ros;


PLUGINLIB_EXPORT_CLASS(sbpl_lattice_planner::SBPLLatticePlanner, nav_core::BaseGlobalPlanner)

namespace geometry_msgs {
  bool operator== (const Point &p1, const Point &p2)
  {
    return p1.x == p2.x && p1.y == p2.y && p1.z == p2.z;
  }
}

namespace sbpl_lattice_planner{

class LatticeSCQ : public StateChangeQuery{
  public:
    LatticeSCQ(EnvironmentNAVXYTHETALAT* env, std::vector<nav2dcell_t> const & changedcellsV)
      : env_(env), changedcellsV_(changedcellsV) {
    }

    // lazy init, because we do not always end up calling this method
    virtual std::vector<int> const * getPredecessors() const{
      if(predsOfChangedCells_.empty() && !changedcellsV_.empty())
        env_->GetPredsofChangedEdges(&changedcellsV_, &predsOfChangedCells_);
      return &predsOfChangedCells_;
    }

    // lazy init, because we do not always end up calling this method
    virtual std::vector<int> const * getSuccessors() const{
      if(succsOfChangedCells_.empty() && !changedcellsV_.empty())
        env_->GetSuccsofChangedEdges(&changedcellsV_, &succsOfChangedCells_);
      return &succsOfChangedCells_;
    }

    EnvironmentNAVXYTHETALAT * env_;
    std::vector<nav2dcell_t> const & changedcellsV_;
    mutable std::vector<int> predsOfChangedCells_;
    mutable std::vector<int> succsOfChangedCells_;
};

SBPLLatticePlanner::SBPLLatticePlanner()
  : initialized_(false), costmap_ros_(NULL){
}

SBPLLatticePlanner::SBPLLatticePlanner(std::string name, costmap_2d::Costmap2DROS* costmap_ros) 
  : initialized_(false), costmap_ros_(NULL){
  initialize(name, costmap_ros);
}

    
void SBPLLatticePlanner::initialize(std::string name, costmap_2d::Costmap2DROS* costmap_ros){
  if(!initialized_){
    ros::NodeHandle private_nh("~/"+name);

    ROS_INFO("Name is %s", name.c_str());

    private_nh.param("planner_type", planner_type_, string("ARAPlanner"));
    private_nh.param("allocated_time", allocated_time_, 10.0);
    private_nh.param("initial_epsilon",initial_epsilon_,3.0);
    private_nh.param("environment_type", environment_type_, string("XYThetaLattice"));
    private_nh.param("forward_search", forward_search_, bool(false));
    private_nh.param("primitive_filename",primitive_filename_,string(""));
    private_nh.param("force_scratch_limit",force_scratch_limit_,500);

    double nominalvel_mpersecs, timetoturn45degsinplace_secs;
    private_nh.param("nominalvel_mpersecs", nominalvel_mpersecs, 0.4);
    private_nh.param("timetoturn45degsinplace_secs", timetoturn45degsinplace_secs, 0.6);

    int lethal_obstacle;
    private_nh.param("lethal_obstacle",lethal_obstacle,20);
    lethal_obstacle_ = (unsigned char) lethal_obstacle;
    inscribed_inflated_obstacle_ = lethal_obstacle_-1;
    sbpl_cost_multiplier_ = (unsigned char) (costmap_2d::INSCRIBED_INFLATED_OBSTACLE/inscribed_inflated_obstacle_ + 1);
    ROS_DEBUG("SBPL: lethal: %uz, inscribed inflated: %uz, multiplier: %uz",lethal_obstacle,inscribed_inflated_obstacle_,sbpl_cost_multiplier_);

    name_ = name;
    costmap_ros_ = costmap_ros;

    footprint_ = costmap_ros_->getRobotFootprint();

    if ("XYThetaLattice" == environment_type_){
      ROS_DEBUG("Using a 3D costmap for theta lattice\n");
      env_ = new EnvironmentNAVXYTHETALAT();
    }
    else{
      ROS_ERROR("XYThetaLattice is currently the only supported environment!\n");
      exit(1);
    }

    circumscribed_cost_ = computeCircumscribedCost();

    if (circumscribed_cost_ == 0) {
      // Unfortunately, the inflation_radius is not taken into account by
      // inflation_layer->computeCost(). If inflation_radius is smaller than
      // the circumscribed radius, SBPL will ignore some obstacles, but we
      // cannot detect this problem. If the cost_scaling_factor is too large,
      // SBPL won't run into obstacles, but will always perform an expensive
      // footprint check, no matter how far the nearest obstacle is.
      ROS_WARN("The costmap value at the robot's circumscribed radius (%f m) is 0.", costmap_ros_->getLayeredCostmap()->getCircumscribedRadius());
      ROS_WARN("SBPL performance will suffer.");
      ROS_WARN("Please decrease the costmap's cost_scaling_factor.");
    }
    if(!env_->SetEnvParameter("cost_inscribed_thresh",costMapCostToSBPLCost(costmap_2d::INSCRIBED_INFLATED_OBSTACLE))){
      ROS_ERROR("Failed to set cost_inscribed_thresh parameter");
      exit(1);
    }
    if(!env_->SetEnvParameter("cost_possibly_circumscribed_thresh", circumscribed_cost_)){
      ROS_ERROR("Failed to set cost_possibly_circumscribed_thresh parameter");
      exit(1);
    }
    int obst_cost_thresh = costMapCostToSBPLCost(costmap_2d::LETHAL_OBSTACLE);
    vector<sbpl_2Dpt_t> perimeterptsV;
    perimeterptsV.reserve(footprint_.size());
    for (size_t ii(0); ii < footprint_.size(); ++ii) {
      sbpl_2Dpt_t pt;
      pt.x = footprint_[ii].x;
      pt.y = footprint_[ii].y;
      perimeterptsV.push_back(pt);
    }

    bool ret;
    try{
      ret = env_->InitializeEnv(costmap_ros_->getCostmap()->getSizeInCellsX(), // width
                                costmap_ros_->getCostmap()->getSizeInCellsY(), // height
                                0, // mapdata
                                0, 0, 0, // start (x, y, theta, t)
                                0, 0, 0, // goal (x, y, theta)
                                0, 0, 0, //goal tolerance
                                perimeterptsV, costmap_ros_->getCostmap()->getResolution(), nominalvel_mpersecs,
                                timetoturn45degsinplace_secs, obst_cost_thresh,
                                primitive_filename_.c_str());
      current_env_width_ = costmap_ros_->getCostmap()->getSizeInCellsX();
      current_env_height_ = costmap_ros_->getCostmap()->getSizeInCellsY();
    }
    catch(SBPL_Exception *e){
      ROS_ERROR("SBPL encountered a fatal exception: %s", e->what());
      ret = false;
    }
    if(!ret){
      ROS_ERROR("SBPL initialization failed!");
      exit(1);
    }
    for (ssize_t ix(0); ix < costmap_ros_->getCostmap()->getSizeInCellsX(); ++ix)
      for (ssize_t iy(0); iy < costmap_ros_->getCostmap()->getSizeInCellsY(); ++iy)
        env_->UpdateCost(ix, iy, costMapCostToSBPLCost(costmap_ros_->getCostmap()->getCost(ix,iy)));

    if ("ARAPlanner" == planner_type_){
      ROS_INFO("Planning with ARA*");
      planner_ = new ARAPlanner(env_, forward_search_);
    }
    else if ("ADPlanner" == planner_type_){
      ROS_INFO("Planning with AD*");
      planner_ = new ADPlanner(env_, forward_search_);
    }
    else{
      ROS_ERROR("ARAPlanner and ADPlanner are currently the only supported planners!\n");
      exit(1);
    }

    ROS_INFO("[sbpl_lattice_planner] Initialized successfully");
    plan_pub_ = private_nh.advertise<nav_msgs::Path>("plan", 1);
    stats_publisher_ = private_nh.advertise<sbpl_lattice_planner::SBPLLatticePlannerStats>("sbpl_lattice_planner_stats", 1);
    
    initialized_ = true;
  }
}
  
//Taken from Sachin's sbpl_cart_planner
//This rescales the costmap according to a rosparam which sets the obstacle cost
unsigned char SBPLLatticePlanner::costMapCostToSBPLCost(unsigned char newcost){
  if(newcost == costmap_2d::LETHAL_OBSTACLE)
    return lethal_obstacle_;
  else if(newcost == costmap_2d::INSCRIBED_INFLATED_OBSTACLE)
    return inscribed_inflated_obstacle_;
  else if(newcost == 0 || newcost == costmap_2d::NO_INFORMATION)
    return 0;
  else {
    unsigned char sbpl_cost = newcost / sbpl_cost_multiplier_;
    if (sbpl_cost == 0)
      sbpl_cost = 1;
    return sbpl_cost;
  }
}

void SBPLLatticePlanner::publishStats(int solution_cost, int solution_size, 
                                      const geometry_msgs::PoseStamped& start, 
                                      const geometry_msgs::PoseStamped& goal){
  // Fill up statistics and publish
  sbpl_lattice_planner::SBPLLatticePlannerStats stats;
  stats.initial_epsilon = initial_epsilon_;
  stats.plan_to_first_solution = false;
  stats.final_number_of_expands = planner_->get_n_expands();
  stats.allocated_time = allocated_time_;

  stats.time_to_first_solution = planner_->get_initial_eps_planning_time();
  stats.actual_time = planner_->get_final_eps_planning_time();
  stats.number_of_expands_initial_solution = planner_->get_n_expands_init_solution();
  stats.final_epsilon = planner_->get_final_epsilon();

  stats.solution_cost = solution_cost;
  stats.path_size = solution_size;
  stats.start = start;
  stats.goal = goal;
  stats_publisher_.publish(stats);
}

unsigned char SBPLLatticePlanner::computeCircumscribedCost() {
  unsigned char result = 0;

  if (!costmap_ros_) {
    ROS_ERROR("Costmap is not initialized");
    return 0;
  }

  // check if the costmap has an inflation layer
  for(std::vector<boost::shared_ptr<costmap_2d::Layer> >::const_iterator layer = costmap_ros_->getLayeredCostmap()->getPlugins()->begin();
      layer != costmap_ros_->getLayeredCostmap()->getPlugins()->end();
      ++layer) {
    boost::shared_ptr<costmap_2d::InflationLayer> inflation_layer = boost::dynamic_pointer_cast<costmap_2d::InflationLayer>(*layer);
    if (!inflation_layer) continue;

    result = costMapCostToSBPLCost(inflation_layer->computeCost(costmap_ros_->getLayeredCostmap()->getCircumscribedRadius() / costmap_ros_->getCostmap()->getResolution()));
  }
  return result;
}

bool SBPLLatticePlanner::makePlan(const geometry_msgs::PoseStamped& start,
                                 const geometry_msgs::PoseStamped& goal,
                                 std::vector<geometry_msgs::PoseStamped>& plan){
  if(!initialized_){
    ROS_ERROR("Global planner is not initialized");
    return false;
  }

  bool do_init = false;
  if (current_env_width_ != costmap_ros_->getCostmap()->getSizeInCellsX() ||
      current_env_height_ != costmap_ros_->getCostmap()->getSizeInCellsY()) {
    ROS_INFO("Costmap dimensions have changed from (%d x %d) to (%d x %d), reinitializing sbpl_lattice_planner.",
             current_env_width_, current_env_height_,
             costmap_ros_->getCostmap()->getSizeInCellsX(), costmap_ros_->getCostmap()->getSizeInCellsY());
    do_init = true;
  }
  else if (footprint_ != costmap_ros_->getRobotFootprint()) {
    ROS_INFO("Robot footprint has changed, reinitializing sbpl_lattice_planner.");
    do_init = true;
  }
  else if (circumscribed_cost_ != computeCircumscribedCost()) {
    ROS_INFO("Cost at circumscribed radius has changed, reinitializing sbpl_lattice_planner.");
    do_init = true;
  }

  if (do_init) {
    initialized_ = false;
    delete planner_;
    planner_ = NULL;
    delete env_;
    env_ = NULL;
    initialize(name_, costmap_ros_);
  }

  plan.clear();

  ROS_INFO("[sbpl_lattice_planner] getting start point (%g,%g) goal point (%g,%g)",
           start.pose.position.x, start.pose.position.y,goal.pose.position.x, goal.pose.position.y);
  double theta_start = 2 * atan2(start.pose.orientation.z, start.pose.orientation.w);
  double theta_goal = 2 * atan2(goal.pose.orientation.z, goal.pose.orientation.w);

  try{
    int ret = env_->SetStart(start.pose.position.x - costmap_ros_->getCostmap()->getOriginX(), start.pose.position.y - costmap_ros_->getCostmap()->getOriginY(), theta_start);
    if(ret < 0 || planner_->set_start(ret) == 0){
      ROS_ERROR("ERROR: failed to set start state\n");
      return false;
    }
  }
  catch(SBPL_Exception *e){
    ROS_ERROR("SBPL encountered a fatal exception while setting the start state");
    return false;
  }

  try{
    int ret = env_->SetGoal(goal.pose.position.x - costmap_ros_->getCostmap()->getOriginX(), goal.pose.position.y - costmap_ros_->getCostmap()->getOriginY(), theta_goal);
    if(ret < 0 || planner_->set_goal(ret) == 0){
      ROS_ERROR("ERROR: failed to set goal state\n");
      return false;
    }
  }
  catch(SBPL_Exception *e){
    ROS_ERROR("SBPL encountered a fatal exception while setting the goal state");
    return false;
  }
  
  int offOnCount = 0;
  int onOffCount = 0;
  int allCount = 0;
  vector<nav2dcell_t> changedcellsV;

  for(unsigned int ix = 0; ix < costmap_ros_->getCostmap()->getSizeInCellsX(); ix++) {
    for(unsigned int iy = 0; iy < costmap_ros_->getCostmap()->getSizeInCellsY(); iy++) {

      unsigned char oldCost = env_->GetMapCost(ix,iy);
      unsigned char newCost = costMapCostToSBPLCost(costmap_ros_->getCostmap()->getCost(ix,iy));

      if(oldCost == newCost) continue;

      allCount++;

      //first case - off cell goes on

      if((oldCost != costMapCostToSBPLCost(costmap_2d::LETHAL_OBSTACLE) && oldCost != costMapCostToSBPLCost(costmap_2d::INSCRIBED_INFLATED_OBSTACLE)) &&
          (newCost == costMapCostToSBPLCost(costmap_2d::LETHAL_OBSTACLE) || newCost == costMapCostToSBPLCost(costmap_2d::INSCRIBED_INFLATED_OBSTACLE))) {
        offOnCount++;
      }

      if((oldCost == costMapCostToSBPLCost(costmap_2d::LETHAL_OBSTACLE) || oldCost == costMapCostToSBPLCost(costmap_2d::INSCRIBED_INFLATED_OBSTACLE)) &&
          (newCost != costMapCostToSBPLCost(costmap_2d::LETHAL_OBSTACLE) && newCost != costMapCostToSBPLCost(costmap_2d::INSCRIBED_INFLATED_OBSTACLE))) {
        onOffCount++;
      }
      env_->UpdateCost(ix, iy, costMapCostToSBPLCost(costmap_ros_->getCostmap()->getCost(ix,iy)));

      nav2dcell_t nav2dcell;
      nav2dcell.x = ix;
      nav2dcell.y = iy;
      changedcellsV.push_back(nav2dcell);
    }
  }

  try{
    if(!changedcellsV.empty()){
      StateChangeQuery* scq = new LatticeSCQ(env_, changedcellsV);
      planner_->costs_changed(*scq);
      delete scq;
    }

    if(allCount > force_scratch_limit_)
      planner_->force_planning_from_scratch();
  }
  catch(SBPL_Exception *e){
    ROS_ERROR("SBPL failed to update the costmap");
    return false;
  }

  //setting planner parameters
  ROS_DEBUG("allocated:%f, init eps:%f\n",allocated_time_,initial_epsilon_);
  planner_->set_initialsolution_eps(initial_epsilon_);
  planner_->set_search_mode(false);

  ROS_DEBUG("[sbpl_lattice_planner] run planner");
  vector<int> solution_stateIDs;
  int solution_cost;
  try{
    int ret = planner_->replan(allocated_time_, &solution_stateIDs, &solution_cost);
    if(ret)
      ROS_DEBUG("Solution is found\n");
    else{
      ROS_INFO("Solution not found\n");
      publishStats(solution_cost, 0, start, goal);
      return false;
    }
  }
  catch(SBPL_Exception *e){
    ROS_ERROR("SBPL encountered a fatal exception while planning");
    return false;
  }

  ROS_DEBUG("size of solution=%d", (int)solution_stateIDs.size());

  vector<EnvNAVXYTHETALAT3Dpt_t> sbpl_path;
  try{
    env_->ConvertStateIDPathintoXYThetaPath(&solution_stateIDs, &sbpl_path);
  }
  catch(SBPL_Exception *e){
    ROS_ERROR("SBPL encountered a fatal exception while reconstructing the path");
    return false;
  }
  // if the plan has zero points, add a single point to make move_base happy
  if( sbpl_path.size() == 0 ) {
    EnvNAVXYTHETALAT3Dpt_t s(
        start.pose.position.x - costmap_ros_->getCostmap()->getOriginX(),
        start.pose.position.y - costmap_ros_->getCostmap()->getOriginY(),
        theta_start);
    sbpl_path.push_back(s);
  }

  ROS_DEBUG("Plan has %d points.\n", (int)sbpl_path.size());
  ros::Time plan_time = ros::Time::now();

  //create a message for the plan 
  nav_msgs::Path gui_path;
  gui_path.poses.resize(sbpl_path.size());
  gui_path.header.frame_id = costmap_ros_->getGlobalFrameID();
  gui_path.header.stamp = plan_time;
  for(unsigned int i=0; i<sbpl_path.size(); i++){
    geometry_msgs::PoseStamped pose;
    pose.header.stamp = plan_time;
    pose.header.frame_id = costmap_ros_->getGlobalFrameID();

    pose.pose.position.x = sbpl_path[i].x + costmap_ros_->getCostmap()->getOriginX();
    pose.pose.position.y = sbpl_path[i].y + costmap_ros_->getCostmap()->getOriginY();
    pose.pose.position.z = start.pose.position.z;

    tf2::Quaternion temp;
    temp.setRPY(0,0,sbpl_path[i].theta);
    pose.pose.orientation.x = temp.getX();
    pose.pose.orientation.y = temp.getY();
    pose.pose.orientation.z = temp.getZ();
    pose.pose.orientation.w = temp.getW();

    plan.push_back(pose);

    gui_path.poses[i] = plan[i];
  }
  plan_pub_.publish(gui_path);
  publishStats(solution_cost, sbpl_path.size(), start, goal);

  return true;
}
};