EDIT: This isn't enough, you need to modify Behavior Tree too. Sorry for misleading before.

---

Did you try with something like:

recoveries_server:
  ros__parameters:
    costmap_topic: local_costmap/costmap_raw
    footprint_topic: local_costmap/published_footprint
    cycle_frequency: 10.0
    recovery_plugins: ["wait"]
    wait:
      plugin: "nav2_recoveries/Wait"
    global_frame: odom
    robot_base_frame: base_link
    transform_timeout: 0.1
    use_sim_time: true

based on:

https://navigation.ros.org/configuration/packages/configuring-behavior-server.html#default-plugins ?

---

Modification of the Behavior Tree - you can use the Groot. For the ROS2 Galactic use:

   cd ~/dev_ws/src
   git clone https://github.com/BehaviorTree/Groot.git
   cd ..
   rosdep install --from-paths src --ignore-src
   colcon build --symlink-install --packages-select groot

I have sudo apt install ros-galactic-behaviortree-cpp-v3 before too.

You have to source install/setup.bash and ./build/groot/Groot.

You can load BT XMLs from the Nav2 repository and modify it, e.g. like this:

root main_tree_to_execute="MainTree">
    <BehaviorTree ID="MainTree">
        <Control ID="RecoveryNode" name="NavigateRecovery" number_of_retries="6">
            <Control ID="PipelineSequence" name="NavigateWithReplanning">
                <Decorator ID="RateController" hz="0.333">
                    <Control ID="RecoveryNode" name="ComputePathThroughPoses" number_of_retries="1">
                        <ReactiveSequence>
                            <Action ID="RemovePassedGoals" input_goals="{goals}" output_goals="{goals}" radius="0.7"/>
                            <Action ID="ComputePathThroughPoses" goals="{goals}" path="{path}" planner_id="GridBased" start=""/>
                        </ReactiveSequence>
                        <ReactiveFallback name="ComputePathThroughPosesRecoveryFallback">
                            <Condition ID="GoalUpdated"/>
                            <Action ID="ClearEntireCostmap" name="ClearGlobalCostmap-Context" service_name="global_costmap/clear_entirely_global_costmap"/>
                        </ReactiveFallback>
                    </Control>
                </Decorator>
                <Control ID="RecoveryNode" name="FollowPath" number_of_retries="1">
                    <Action ID="FollowPath" controller_id="FollowPath" goal_checker_id="GoalChecker" path="{path}"/>
                    <ReactiveFallback name="FollowPathRecoveryFallback">
                        <Condition ID="GoalUpdated"/>
                        <Action ID="ClearEntireCostmap" name="ClearLocalCostmap-Context" service_name="local_costmap/clear_entirely_local_costmap"/>
                    </ReactiveFallback>
                </Control>
            </Control>
            <ReactiveFallback name="RecoveryFallback">
                <Condition ID="GoalUpdated"/>
                <Control ID="RoundRobin" name="RecoveryActions">
                    <Sequence name="ClearingActions">
                        <Action ID="ClearEntireCostmap" name="ClearLocalCostmap-Subtree" service_name="local_costmap/clear_entirely_local_costmap"/>
                        <Action ID="ClearEntireCostmap" name="ClearGlobalCostmap-Subtree" service_name="global_costmap/clear_entirely_global_costmap"/>
                    </Sequence>
                    <Action ID="Wait" wait_duration="5"/>
                </Control>
            </ReactiveFallback>
        </Control>
    </BehaviorTree>
</root>

Comments

That wouldn't be sufficient, you need to remove spin / backup from the behavior tree XML file you're using as well so its not trying to call those behaviors. The Behavior Tree is what actually defines the navigation logic.

Asked by stevemacenski on 2022-05-02 16:07:18 UTC

The behavior tree decides what to do. The default behavior tree has a spin and backup in the RecoveryFallback.

What you're doing isn't changing the behavior tree, but changing what plugin is linked to what name. You're removing the plugins without removing the reference to them in the behavior tree.

You'll need to make your own behavior tree without the spin and backup plugins and use that in Nav2.

Comments