Draft: Added GoalUpdatedController BT plugin node

nav2_behavior_tree/CMakeLists.txt

@@ -180,6 +180,9 @@ list(APPEND plugin_libs nav2_controller_selector_bt_node)
 add_library(nav2_goal_checker_selector_bt_node SHARED plugins/action/goal_checker_selector_node.cpp)
 list(APPEND plugin_libs nav2_goal_checker_selector_bt_node)
 
+add_library(nav2_goal_updated_controller_bt_node SHARED plugins/decorator/goal_updated_controller.cpp)
+list(APPEND plugin_libs nav2_goal_updated_controller_bt_node)
+
 foreach(bt_plugin ${plugin_libs})
   ament_target_dependencies(${bt_plugin} ${dependencies})
   target_compile_definitions(${bt_plugin} PRIVATE BT_PLUGIN_EXPORT)

nav2_behavior_tree/include/nav2_behavior_tree/plugins/decorator/goal_updated_controller.hpp

@@ -0,0 +1,69 @@
+// Copyright (c) 2018 Intel Corporation
+//
+// 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.
+
+#ifndef NAV2_BEHAVIOR_TREE__PLUGINS__DECORATOR__GOAL_UPDATED_CONTROLLER_HPP_
+#define NAV2_BEHAVIOR_TREE__PLUGINS__DECORATOR__GOAL_UPDATED_CONTROLLER_HPP_
+
+#include <chrono>
+#include <string>
+#include <vector>
+
+#include "behaviortree_cpp_v3/decorator_node.h"
+
+#include "rclcpp/rclcpp.hpp"
+#include "geometry_msgs/msg/pose_stamped.hpp"
+
+namespace nav2_behavior_tree
+{
+
+/**
+ * @brief A BT::DecoratorNode that ticks its child if the goal was updated
+ */
+class GoalUpdatedController : public BT::DecoratorNode
+{
+public:
+  /**
+   * @brief A constructor for nav2_behavior_tree::GoalUpdatedController
+   * @param name Name for the XML tag for this node
+   * @param conf BT node configuration
+   */
+  GoalUpdatedController(
+    const std::string & name,
+    const BT::NodeConfiguration & conf);
+
+  /**
+   * @brief Creates list of BT ports
+   * @return BT::PortsList Containing node-specific ports
+   */
+  static BT::PortsList providedPorts()
+  {
+    return {};
+  }
+
+private:
+  /**
+   * @brief The main override required by a BT action
+   * @return BT::NodeStatus Status of tick execution
+   */
+  BT::NodeStatus tick() override;
+
+  bool first_time_;
+  bool goal_was_updated_;
+  geometry_msgs::msg::PoseStamped goal_;
+  std::vector<geometry_msgs::msg::PoseStamped> goals_;
+};
+
+}  // namespace nav2_behavior_tree
+
+#endif  // NAV2_BEHAVIOR_TREE__PLUGINS__DECORATOR__GOAL_UPDATED_CONTROLLER_HPP_

nav2_behavior_tree/plugins/decorator/goal_updated_controller.cpp

@@ -0,0 +1,93 @@
+// Copyright (c) 2018 Intel Corporation
+//
+// 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 <chrono>
+#include <string>
+
+#include "rclcpp/rclcpp.hpp"
+#include "geometry_msgs/msg/pose_stamped.hpp"
+#include "behaviortree_cpp_v3/decorator_node.h"
+#include "nav2_behavior_tree/plugins/decorator/goal_updated_controller.hpp"
+
+
+namespace nav2_behavior_tree
+{
+
+GoalUpdatedController::GoalUpdatedController(
+  const std::string & name,
+  const BT::NodeConfiguration & conf)
+: BT::DecoratorNode(name, conf),
+first_time_(false)
+{
+}
+
+BT::NodeStatus GoalUpdatedController::tick()
+{
+  if (status() == BT::NodeStatus::IDLE) {
+    // Reset since we're starting a new iteration of
+    // the goal updated controller (moving from IDLE to RUNNING)
+    first_time_ = true;
+    goal_was_updated_ = false;
+  }
+
+  setStatus(BT::NodeStatus::RUNNING);
+
+  if (first_time_) {
+    config().blackboard->get<std::vector<geometry_msgs::msg::PoseStamped>>("goals", goals_);
+    config().blackboard->get<geometry_msgs::msg::PoseStamped>("goal", goal_);
+  }
+
+  std::vector<geometry_msgs::msg::PoseStamped> current_goals;
+  config().blackboard->get<std::vector<geometry_msgs::msg::PoseStamped>>("goals", current_goals);
+  geometry_msgs::msg::PoseStamped current_goal;
+  config().blackboard->get<geometry_msgs::msg::PoseStamped>("goal", current_goal);
+
+  if (goal_ != current_goal || goals_ != current_goals) {
+    goal_ = current_goal;
+    goals_ = current_goals;
+    goal_was_updated_ = true;
+  }
+
+  // The child gets ticked the first time through and any time the goal has
+  // changed or preempted. In addition, once the child begins to run, it is ticked each time
+  // 'til completion
+  if (first_time_ || (child_node_->status() == BT::NodeStatus::RUNNING) || goal_was_updated_)
+  {
+    first_time_ = false;
+    goal_was_updated_ = false;
+    const BT::NodeStatus child_state = child_node_->executeTick();
+
+    switch (child_state) {
+      case BT::NodeStatus::RUNNING:
+        return BT::NodeStatus::RUNNING;
+
+      case BT::NodeStatus::SUCCESS:
+        return BT::NodeStatus::SUCCESS;
+
+      case BT::NodeStatus::FAILURE:
+      default:
+        return BT::NodeStatus::FAILURE;
+    }
+  }
+
+  return status();
+}
+
+}  // namespace nav2_behavior_tree
+
+#include "behaviortree_cpp_v3/bt_factory.h"
+BT_REGISTER_NODES(factory)
+{
+  factory.registerNodeType<nav2_behavior_tree::GoalUpdatedController>("GoalUpdatedController");
+}

nav2_bringup/params/nav2_params.yaml

@@ -82,6 +82,7 @@ bt_navigator:
     - nav2_path_expiring_timer_condition
     - nav2_distance_traveled_condition_bt_node
     - nav2_single_trigger_bt_node
+    - nav2_goal_updated_controller_bt_node
     - nav2_is_battery_low_condition_bt_node
     - nav2_navigate_through_poses_action_bt_node
     - nav2_navigate_to_pose_action_bt_node

nav2_bt_navigator/behavior_trees/navigate_w_replanning_only_if_goal_is_updated.xml

@@ -0,0 +1,14 @@
+<!--
+  This Behavior Tree replans the global path only when the goal is updated.
+-->
+
+<root main_tree_to_execute="MainTree">
+  <BehaviorTree ID="MainTree">
+    <PipelineSequence name="NavigateWithReplanning">
+      <GoalUpdatedController> <!-- only tick child if goal was updated-->
+        <ComputePathToPose goal="{goal}" path="{path}" planner_id="GridBased"/>
+      </GoalUpdatedController>
+      <FollowPath path="{path}"  controller_id="FollowPath"/>
+    </PipelineSequence>
+  </BehaviorTree>
+</root>