rotate_to_goal.cpp

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#include "dwb_critics/rotate_to_goal.hpp"
#include <string>
#include <vector>
#include "dwb_core/exceptions.hpp"
#include "pluginlib/class_list_macros.hpp"
#include "dwb_core/trajectory_utils.hpp"
#include "nav2_util/geometry_utils.hpp"
#include "angles/angles.h"
 
PLUGINLIB_EXPORT_CLASS(dwb_critics::RotateToGoalCritic, dwb_core::TrajectoryCritic)
 
namespace dwb_critics
{
 
inline double hypot_sq(double dx, double dy)
{
  return dx * dx + dy * dy;
}
 
void RotateToGoalCritic::onInit()
{
  auto node = node_.lock();
  if (!node) {
    throw std::runtime_error{"Failed to lock node"};
  }
 
  xy_goal_tolerance_ = node->declare_or_get_parameter(
    dwb_plugin_name_ + ".xy_goal_tolerance", 0.25);
  xy_goal_tolerance_sq_ = xy_goal_tolerance_ * xy_goal_tolerance_;
  path_length_tolerance_ = node->declare_or_get_parameter(
    dwb_plugin_name_ + "path_length_tolerance", 1.0);
  double stopped_xy_velocity = node->declare_or_get_parameter(
    dwb_plugin_name_ + ".trans_stopped_velocity", 0.25);
  stopped_xy_velocity_sq_ = stopped_xy_velocity * stopped_xy_velocity;
  slowing_factor_ = node->declare_or_get_parameter(
    dwb_plugin_name_ + "." + name_ + ".slowing_factor", 5.0);
  lookahead_time_ = node->declare_or_get_parameter(
    dwb_plugin_name_ + "." + name_ + ".lookahead_time", -1.0);
  reset();
}
 
void RotateToGoalCritic::reset()
{
  in_window_ = false;
  rotating_ = false;
}
 
bool RotateToGoalCritic::prepare(
  const geometry_msgs::msg::Pose & pose, const nav_2d_msgs::msg::Twist2D & vel,
  const geometry_msgs::msg::Pose & goal,
  const nav_msgs::msg::Path & transformed_global_plan)
{
  double dxy_sq = hypot_sq(pose.position.x - goal.position.x, pose.position.y - goal.position.y);
  double path_length = nav2_util::geometry_utils::calculate_path_length(transformed_global_plan);
  in_window_ = in_window_ ||
    (dxy_sq <= xy_goal_tolerance_sq_ && path_length <= path_length_tolerance_);
  current_xy_speed_sq_ = hypot_sq(vel.x, vel.y);
  rotating_ = rotating_ || (in_window_ && current_xy_speed_sq_ <= stopped_xy_velocity_sq_);
  goal_yaw_ = tf2::getYaw(goal.orientation);
  return true;
}
 
double RotateToGoalCritic::scoreTrajectory(const dwb_msgs::msg::Trajectory2D & traj)
{
  // If we're not sufficiently close to the goal, we don't care what the twist is
  if (!in_window_) {
    return 0.0;
  } else if (!rotating_) {
    double speed_sq = hypot_sq(traj.velocity.x, traj.velocity.y);
    if (speed_sq >= current_xy_speed_sq_) {
      throw dwb_core::IllegalTrajectoryException(name_, "Not slowing down near goal.");
    }
    return speed_sq * slowing_factor_ + scoreRotation(traj);
  }
 
  // If we're sufficiently close to the goal, any transforming velocity is invalid
  if (fabs(traj.velocity.x) > 0 || fabs(traj.velocity.y) > 0) {
    throw dwb_core::
          IllegalTrajectoryException(name_, "Nonrotation command near goal.");
  }
 
  return scoreRotation(traj);
}
 
double RotateToGoalCritic::scoreRotation(const dwb_msgs::msg::Trajectory2D & traj)
{
  if (traj.poses.empty()) {
    throw dwb_core::IllegalTrajectoryException(name_, "Empty trajectory.");
  }
 
  double end_yaw;
  if (lookahead_time_ >= 0.0) {
    geometry_msgs::msg::Pose eval_pose = dwb_core::projectPose(traj, lookahead_time_);
    end_yaw = tf2::getYaw(eval_pose.orientation);
  } else {
    end_yaw = tf2::getYaw(traj.poses.back().orientation);
  }
  return fabs(angles::shortest_angular_distance(end_yaw, goal_yaw_));
}
 
}  // namespace dwb_critics