Program Listing for File standard_traj_generator.hpp

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#ifndef DWB_PLUGINS__STANDARD_TRAJ_GENERATOR_HPP_
#define DWB_PLUGINS__STANDARD_TRAJ_GENERATOR_HPP_

#include <vector>
#include <memory>
#include <string>

#include "rclcpp/rclcpp.hpp"
#include "dwb_core/trajectory_generator.hpp"
#include "dwb_plugins/velocity_iterator.hpp"
#include "dwb_plugins/kinematic_parameters.hpp"
#include "nav2_util/lifecycle_node.hpp"

namespace dwb_plugins
{

class StandardTrajectoryGenerator : public dwb_core::TrajectoryGenerator
{
public:
  // Standard TrajectoryGenerator interface
  void initialize(
    const nav2_util::LifecycleNode::SharedPtr & nh,
    const std::string & plugin_name) override;
  void startNewIteration(const nav_2d_msgs::msg::Twist2D & current_velocity) override;
  bool hasMoreTwists() override;
  nav_2d_msgs::msg::Twist2D nextTwist() override;

  dwb_msgs::msg::Trajectory2D generateTrajectory(
    const geometry_msgs::msg::Pose2D & start_pose,
    const nav_2d_msgs::msg::Twist2D & start_vel,
    const nav_2d_msgs::msg::Twist2D & cmd_vel) override;

  void setSpeedLimit(const double & speed_limit, const bool & percentage) override
  {
    if (kinematics_handler_) {
      kinematics_handler_->setSpeedLimit(speed_limit, percentage);
    }
  }

protected:
  virtual void initializeIterator(const nav2_util::LifecycleNode::SharedPtr & nh);

  virtual nav_2d_msgs::msg::Twist2D computeNewVelocity(
    const nav_2d_msgs::msg::Twist2D & cmd_vel, const nav_2d_msgs::msg::Twist2D & start_vel,
    const double dt);

  virtual geometry_msgs::msg::Pose2D computeNewPosition(
    const geometry_msgs::msg::Pose2D start_pose, const nav_2d_msgs::msg::Twist2D & vel,
    const double dt);


  virtual std::vector<double> getTimeSteps(const nav_2d_msgs::msg::Twist2D & cmd_vel);

  KinematicsHandler::Ptr kinematics_handler_;
  std::shared_ptr<VelocityIterator> velocity_iterator_;

  double sim_time_;

  // Sampling Parameters
  bool discretize_by_time_;

  double time_granularity_;

  double linear_granularity_;

  double angular_granularity_;

  std::string plugin_name_;

  /* Backwards Compatibility Parameter: include_last_point
   *
   * dwa had an off-by-one error built into it.
   * It generated N trajectory points, where N = ceil(sim_time / time_delta).
   * If for example, sim_time=3.0 and time_delta=1.5, it would generate trajectories with 2 points, which
   * indeed were time_delta seconds apart. However, the points would be at t=0 and t=1.5, and thus the
   * actual sim_time was much less than advertised.
   *
   * This is remedied by adding one final point at t=sim_time, but only if include_last_point_ is true.
   *
   * Nothing I could find actually used the time_delta variable or seemed to care that the trajectories
   * were not projected out as far as they intended.
   */
  bool include_last_point_;
};


}  // namespace dwb_plugins

#endif  // DWB_PLUGINS__STANDARD_TRAJ_GENERATOR_HPP_