waypoint_follower.cpp

// Copyright (c) 2019 Samsung Research America
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#include "nav2_waypoint_follower/waypoint_follower.hpp"
 
#include <fstream>
#include <memory>
#include <streambuf>
#include <string>
#include <utility>
#include <vector>
 
#include "nav2_ros_common/rate.hpp"
 
namespace nav2_waypoint_follower
{
 
using rcl_interfaces::msg::ParameterType;
using std::placeholders::_1;
 
WaypointFollower::WaypointFollower(const rclcpp::NodeOptions & options)
: nav2::LifecycleNode("waypoint_follower", "", options),
  waypoint_task_executor_loader_("nav2_core",
    "nav2_core::WaypointTaskExecutor")
{
  RCLCPP_INFO(get_logger(), "Creating");
}
 
WaypointFollower::~WaypointFollower()
{
}
 
nav2::CallbackReturn
WaypointFollower::on_configure(const rclcpp_lifecycle::State & state)
{
  RCLCPP_INFO(get_logger(), "Configuring");
 
  auto node = shared_from_this();
 
  param_handler_ = std::make_unique<ParameterHandler>(
    node, get_logger());
  params_ = param_handler_->getParams();
 
  callback_group_ = create_callback_group(
    rclcpp::CallbackGroupType::MutuallyExclusive,
    false);
  callback_group_executor_.add_callback_group(callback_group_, get_node_base_interface());
 
  nav_to_pose_client_ = create_action_client<ClientT>(
    "navigate_to_pose", callback_group_);
 
  xyz_action_server_ = create_action_server<ActionT>(
    "follow_waypoints", std::bind(
      &WaypointFollower::followWaypointsCallback,
      this),
    std::bind(&WaypointFollower::goalReceived<ActionT>, this, std::placeholders::_1),
    nullptr, std::chrono::milliseconds(
      500), false);
 
  from_ll_to_map_client_ = node->create_client<robot_localization::srv::FromLL>(
    "/fromLL",
    true /*creates and spins an internal executor*/);
 
  gps_action_server_ = create_action_server<ActionTGPS>(
    "follow_gps_waypoints",
    std::bind(
      &WaypointFollower::followGPSWaypointsCallback,
      this),
    std::bind(&WaypointFollower::goalReceived<ActionTGPS>, this, std::placeholders::_1),
    nullptr, std::chrono::milliseconds(
      500), false);
 
  try {
    waypoint_task_executor_ = waypoint_task_executor_loader_.createUniqueInstance(
      params_->waypoint_task_executor_type);
    RCLCPP_INFO(
      get_logger(), "Created waypoint_task_executor : %s of type %s",
      params_->waypoint_task_executor_id.c_str(), params_->waypoint_task_executor_type.c_str());
    waypoint_task_executor_->initialize(node, params_->waypoint_task_executor_id);
  } catch (const std::exception & e) {
    RCLCPP_FATAL(
      get_logger(),
      "Failed to create waypoint_task_executor. Exception: %s", e.what());
    on_cleanup(state);
    return nav2::CallbackReturn::FAILURE;
  }
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
WaypointFollower::on_activate(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Activating");
 
  xyz_action_server_->activate();
  gps_action_server_->activate();
 
  // create bond connection
  createBond();
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
WaypointFollower::on_deactivate(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Deactivating");
 
  xyz_action_server_->deactivate();
  gps_action_server_->deactivate();
  // destroy bond connection
  destroyBond();
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
WaypointFollower::on_cleanup(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Cleaning up");
 
  xyz_action_server_.reset();
  nav_to_pose_client_.reset();
  gps_action_server_.reset();
  from_ll_to_map_client_.reset();
 
  return nav2::CallbackReturn::SUCCESS;
}
 
nav2::CallbackReturn
WaypointFollower::on_shutdown(const rclcpp_lifecycle::State & /*state*/)
{
  RCLCPP_INFO(get_logger(), "Shutting down");
  return nav2::CallbackReturn::SUCCESS;
}
 
template<typename T>
bool WaypointFollower::goalReceived(std::shared_ptr<const typename T::Goal> goal)
{
  if constexpr (std::is_same_v<T, ActionTGPS>) {
    if (goal->gps_poses.empty()) {
      RCLCPP_ERROR(
        get_logger(), "Empty vector of GPS waypoints passed to waypoint following action.");
      return false;
    }
  } else {
    if (goal->poses.empty()) {
      RCLCPP_ERROR(
        get_logger(), "Empty vector of waypoints passed to waypoint following action.");
      return false;
    }
  }
  return true;
}
 
template<typename T>
std::vector<geometry_msgs::msg::PoseStamped> WaypointFollower::getLatestGoalPoses(
  const T & action_server)
{
  std::vector<geometry_msgs::msg::PoseStamped> poses;
  const auto current_goal = action_server->get_current_goal();
 
  if (!current_goal) {
    RCLCPP_ERROR(get_logger(), "No current action goal found!");
    return poses;
  }
 
  // compile time static check to decide which block of code to be built
  if constexpr (std::is_same<T, ActionServer::SharedPtr>::value) {
    // If normal waypoint following callback was called, we build here
    poses = current_goal->poses;
  } else {
    // If GPS waypoint following callback was called, we build here
    poses = convertGPSPosesToMapPoses(
      current_goal->gps_poses);
  }
  return poses;
}
 
template<typename T, typename V, typename Z>
void WaypointFollower::followWaypointsHandler(
  const T & action_server,
  const V & feedback,
  const Z & result)
{
  auto goal = action_server->get_current_goal();
 
  // handling loops
  unsigned int current_loop_no = 0;
  auto no_of_loops = goal->number_of_loops;
 
  std::vector<geometry_msgs::msg::PoseStamped> poses;
  poses = getLatestGoalPoses<T>(action_server);
 
  if (!action_server || !action_server->is_server_active()) {
    RCLCPP_DEBUG(get_logger(), "Action server inactive. Stopping.");
    return;
  }
 
  RCLCPP_INFO(
    get_logger(), "Received follow waypoint request with %i waypoints.",
    static_cast<int>(poses.size()));
 
  // Check again, GPS waypoint following the poses may still be empty if conversion failed
  if (poses.empty()) {
    result->error_code =
      nav2_msgs::action::FollowWaypoints::Result::NO_VALID_WAYPOINTS;
    result->error_msg =
      "Empty vector of waypoints, probably due to conversion failure.";
    RCLCPP_ERROR(get_logger(), "%s", result->error_msg.c_str());
    action_server->terminate_current(result);
    return;
  }
 
  nav2::Rate r(this, params_->loop_rate);
 
  // get the goal index, by default, the first in the list of waypoints given.
  uint32_t goal_index = goal->goal_index;
  bool new_goal = true;
 
  while (rclcpp::ok()) {
    // Check if asked to stop processing action
    if (action_server->is_cancel_requested()) {
      auto cancel_future = nav_to_pose_client_->async_cancel_all_goals();
      callback_group_executor_.spin_until_future_complete(cancel_future);
      // for result callback processing
      callback_group_executor_.spin_some();
      action_server->terminate_all();
      return;
    }
 
    // Check if asked to process another action
    if (action_server->is_preempt_requested()) {
      RCLCPP_INFO(get_logger(), "Preempting the goal pose.");
      goal = action_server->accept_pending_goal();
      poses = getLatestGoalPoses<T>(action_server);
      if (poses.empty()) {
        result->error_code =
          nav2_msgs::action::FollowWaypoints::Result::NO_VALID_WAYPOINTS;
        result->error_msg =
          "Empty vector of Waypoints passed to waypoint following logic. "
          "Nothing to execute, returning with failure!";
        RCLCPP_ERROR(get_logger(), "%s", result->error_msg.c_str());
        action_server->terminate_current(result);
        return;
      }
      goal_index = 0;
      new_goal = true;
    }
 
    // Check if we need to send a new goal
    if (new_goal) {
      new_goal = false;
      ClientT::Goal client_goal;
      client_goal.pose = poses[goal_index];
      client_goal.pose.header.stamp = this->now();
 
      auto send_goal_options = nav2::ActionClient<ClientT>::SendGoalOptions();
      send_goal_options.result_callback = std::bind(
        &WaypointFollower::resultCallback, this,
        std::placeholders::_1);
      send_goal_options.goal_response_callback = std::bind(
        &WaypointFollower::goalResponseCallback,
        this, std::placeholders::_1);
 
      future_goal_handle_ =
        nav_to_pose_client_->async_send_goal(client_goal, send_goal_options);
      current_goal_status_.status = ActionStatus::PROCESSING;
    }
 
    feedback->current_waypoint = goal_index;
    action_server->publish_feedback(feedback);
 
    if (
      current_goal_status_.status == ActionStatus::FAILED ||
      current_goal_status_.status == ActionStatus::UNKNOWN)
    {
      nav2_msgs::msg::WaypointStatus missedWaypoint;
      missedWaypoint.waypoint_status = nav2_msgs::msg::WaypointStatus::FAILED;
      missedWaypoint.waypoint_index = goal_index;
      missedWaypoint.waypoint_pose = poses[goal_index];
      missedWaypoint.error_code = current_goal_status_.error_code;
      missedWaypoint.error_msg = current_goal_status_.error_msg;
      result->missed_waypoints.push_back(missedWaypoint);
 
      if (params_->stop_on_failure) {
        result->error_code =
          nav2_msgs::action::FollowWaypoints::Result::STOP_ON_MISSED_WAYPOINT;
        result->error_msg =
          "Failed to process waypoint " + std::to_string(goal_index) +
          " in waypoint list and stop on failure is enabled."
          " Terminating action.";
        RCLCPP_WARN(get_logger(), "%s", result->error_msg.c_str());
        action_server->terminate_current(result);
        current_goal_status_.error_code = 0;
        current_goal_status_.error_msg = "";
        return;
      } else {
        RCLCPP_INFO(
          get_logger(), "Failed to process waypoint %i,"
          " moving to next.", goal_index);
      }
    } else if (current_goal_status_.status == ActionStatus::SUCCEEDED) {
      RCLCPP_INFO(
        get_logger(), "Succeeded processing waypoint %i, processing waypoint task execution",
        goal_index);
      bool is_task_executed = waypoint_task_executor_->processAtWaypoint(
        poses[goal_index], goal_index);
      RCLCPP_INFO(
        get_logger(), "Task execution at waypoint %i %s", goal_index,
        is_task_executed ? "succeeded" : "failed!");
 
      if (!is_task_executed) {
        nav2_msgs::msg::WaypointStatus missedWaypoint;
        missedWaypoint.waypoint_status = nav2_msgs::msg::WaypointStatus::FAILED;
        missedWaypoint.waypoint_index = goal_index;
        missedWaypoint.waypoint_pose = poses[goal_index];
        missedWaypoint.error_code =
          nav2_msgs::action::FollowWaypoints::Result::TASK_EXECUTOR_FAILED;
        missedWaypoint.error_msg = "Task execution failed";
        result->missed_waypoints.push_back(missedWaypoint);
      }
      // if task execution was failed and stop_on_failure_ is on , terminate action
      if (!is_task_executed && params_->stop_on_failure) {
        result->error_code =
          nav2_msgs::action::FollowWaypoints::Result::TASK_EXECUTOR_FAILED;
        result->error_msg =
          "Failed to execute task at waypoint " + std::to_string(goal_index) +
          " stop on failure is enabled. Terminating action.";
        RCLCPP_WARN(get_logger(), "%s", result->error_msg.c_str());
        action_server->terminate_current(result);
        current_goal_status_.error_code = 0;
        current_goal_status_.error_msg = "";
        return;
      } else {
        RCLCPP_INFO(
          get_logger(), "Handled task execution on waypoint %i,"
          " moving to next.", goal_index);
      }
    }
 
    if (current_goal_status_.status != ActionStatus::PROCESSING) {
      // Update server state
      goal_index++;
      new_goal = true;
      if (goal_index >= poses.size()) {
        if (current_loop_no == no_of_loops) {
          RCLCPP_INFO(
            get_logger(), "Completed all %zu waypoints requested.",
            poses.size());
          action_server->succeeded_current(result);
          current_goal_status_.error_code = 0;
          current_goal_status_.error_msg = "";
          return;
        }
        RCLCPP_INFO(
          get_logger(), "Starting a new loop, current loop count is %i",
          current_loop_no);
        goal_index = 0;
        current_loop_no++;
      }
    }
 
    callback_group_executor_.spin_some();
    r.sleep();
  }
}
 
void WaypointFollower::followWaypointsCallback()
{
  auto feedback = std::make_shared<ActionT::Feedback>();
  auto result = std::make_shared<ActionT::Result>();
 
  followWaypointsHandler<typename ActionServer::SharedPtr,
    ActionT::Feedback::SharedPtr,
    ActionT::Result::SharedPtr>(
    xyz_action_server_,
    feedback, result);
}
 
void WaypointFollower::followGPSWaypointsCallback()
{
  auto feedback = std::make_shared<ActionTGPS::Feedback>();
  auto result = std::make_shared<ActionTGPS::Result>();
 
  followWaypointsHandler<typename ActionServerGPS::SharedPtr,
    ActionTGPS::Feedback::SharedPtr,
    ActionTGPS::Result::SharedPtr>(
    gps_action_server_,
    feedback, result);
}
 
void
WaypointFollower::resultCallback(
  const rclcpp_action::ClientGoalHandle<ClientT>::WrappedResult & result)
{
  if (result.goal_id != future_goal_handle_.get()->get_goal_id()) {
    RCLCPP_DEBUG(
      get_logger(),
      "Goal IDs do not match for the current goal handle and received result."
      "Ignoring likely due to receiving result for an old goal.");
    return;
  }
 
  switch (result.code) {
    case rclcpp_action::ResultCode::SUCCEEDED:
      current_goal_status_.status = ActionStatus::SUCCEEDED;
      return;
    case rclcpp_action::ResultCode::ABORTED:
      current_goal_status_.status = ActionStatus::FAILED;
      current_goal_status_.error_code = result.result->error_code;
      current_goal_status_.error_msg = result.result->error_msg;
      return;
    case rclcpp_action::ResultCode::CANCELED:
      current_goal_status_.status = ActionStatus::FAILED;
      return;
    default:
      current_goal_status_.status = ActionStatus::UNKNOWN;
      current_goal_status_.error_code = nav2_msgs::action::FollowWaypoints::Result::UNKNOWN;
      current_goal_status_.error_msg = "Received an UNKNOWN result code from navigation action!";
      RCLCPP_ERROR(get_logger(), "%s", current_goal_status_.error_msg.c_str());
      return;
  }
}
 
void
WaypointFollower::goalResponseCallback(
  const rclcpp_action::ClientGoalHandle<ClientT>::SharedPtr & goal)
{
  if (!goal) {
    current_goal_status_.status = ActionStatus::FAILED;
    current_goal_status_.error_code = nav2_msgs::action::FollowWaypoints::Result::UNKNOWN;
    current_goal_status_.error_msg =
      "navigate_to_pose action client failed to send goal to server.";
    RCLCPP_ERROR(get_logger(), "%s", current_goal_status_.error_msg.c_str());
  }
}
 
std::vector<geometry_msgs::msg::PoseStamped>
WaypointFollower::convertGPSPosesToMapPoses(
  const std::vector<geographic_msgs::msg::GeoPose> & gps_poses)
{
  RCLCPP_INFO(
    this->get_logger(), "Converting GPS waypoints to %s Frame..",
    params_->global_frame_id.c_str());
 
  std::vector<geometry_msgs::msg::PoseStamped> poses_in_map_frame_vector;
  int waypoint_index = 0;
  for (auto && curr_geopose : gps_poses) {
    auto request = std::make_shared<robot_localization::srv::FromLL::Request>();
    auto response = std::make_shared<robot_localization::srv::FromLL::Response>();
    request->ll_point.latitude = curr_geopose.position.latitude;
    request->ll_point.longitude = curr_geopose.position.longitude;
    request->ll_point.altitude = curr_geopose.position.altitude;
 
    from_ll_to_map_client_->wait_for_service((std::chrono::seconds(1)));
    if (!from_ll_to_map_client_->invoke(request, response)) {
      RCLCPP_ERROR(
        this->get_logger(),
        "fromLL service of robot_localization could not convert %i th GPS waypoint to"
        "%s frame, going to skip this point!"
        "Make sure you have run navsat_transform_node of robot_localization",
        waypoint_index, params_->global_frame_id.c_str());
      if (params_->stop_on_failure) {
        RCLCPP_ERROR(
          this->get_logger(),
          "Conversion of %i th GPS waypoint to"
          "%s frame failed and stop_on_failure is set to true"
          "Not going to execute any of waypoints, exiting with failure!",
          waypoint_index, params_->global_frame_id.c_str());
        return std::vector<geometry_msgs::msg::PoseStamped>();
      }
      continue;
    } else {
      geometry_msgs::msg::PoseStamped curr_pose_map_frame;
      curr_pose_map_frame.header.frame_id = params_->global_frame_id;
      curr_pose_map_frame.header.stamp = this->now();
      curr_pose_map_frame.pose.position = response->map_point;
      curr_pose_map_frame.pose.orientation = curr_geopose.orientation;
      poses_in_map_frame_vector.push_back(curr_pose_map_frame);
    }
    waypoint_index++;
  }
  RCLCPP_INFO(
    this->get_logger(),
    "Converted all %i GPS waypoint to %s frame",
    static_cast<int>(poses_in_map_frame_vector.size()), params_->global_frame_id.c_str());
  return poses_in_map_frame_vector;
}
 
}  // namespace nav2_waypoint_follower
 
#include "rclcpp_components/register_node_macro.hpp"
 
// Register the component with class_loader.
// This acts as a sort of entry point, allowing the component to be discoverable when its library
// is being loaded into a running process.
RCLCPP_COMPONENTS_REGISTER_NODE(nav2_waypoint_follower::WaypointFollower)