-
 

Package Summary

Tags No category tags.
Version 1.1.16
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version humble
Last Updated 2024-10-04
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

TODO

Additional Links

No additional links.

Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

No additional authors.

nav2_behavior_tree

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees for either navigation or autonomy systems. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The nav2_behavior_tree module provides:

  • A C++ template class for easily integrating ROS2 actions and services into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes for navigation or higher-level autonomy applications.

See its Configuration Guide Page for additional parameter descriptions and a list of XML nodes made available in this package. Also review the Nav2 Behavior Tree Explanation pages explaining more context on the default behavior trees and examples provided in this package. A tutorial is also provided to explain how to create a simple BT plugin.

See the Navigation Plugin list for a list of the currently known and available planner plugins.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BtActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}" controller_property="FollowPath"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/docs/3.8/learn-the-basics/BT_basics

CHANGELOG

Wiki Tutorials

This package does not provide any links to tutorials in it's rosindex metadata. You can check on the ROS Wiki Tutorials page for the package.

Launch files

No launch files found

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged nav2_behavior_tree at Robotics Stack Exchange

Package Summary

Tags No category tags.
Version 1.2.10
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version iron
Last Updated 2024-10-02
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

TODO

Additional Links

No additional links.

Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

No additional authors.

nav2_behavior_tree

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees for either navigation or autonomy systems. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The nav2_behavior_tree module provides:

  • A C++ template class for easily integrating ROS2 actions and services into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes for navigation or higher-level autonomy applications.

See its Configuration Guide Page for additional parameter descriptions and a list of XML nodes made available in this package. Also review the Nav2 Behavior Tree Explanation pages explaining more context on the default behavior trees and examples provided in this package. A tutorial is also provided to explain how to create a simple BT plugin.

See the Navigation Plugin list for a list of the currently known and available planner plugins.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BtActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}" controller_property="FollowPath"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/docs/3.8/learn-the-basics/BT_basics

CHANGELOG

Wiki Tutorials

This package does not provide any links to tutorials in it's rosindex metadata. You can check on the ROS Wiki Tutorials page for the package.

Launch files

No launch files found

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged nav2_behavior_tree at Robotics Stack Exchange

Package Summary

Tags No category tags.
Version 1.3.2
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version jazzy
Last Updated 2024-10-02
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

Nav2 behavior tree wrappers, nodes, and utilities

Additional Links

No additional links.

Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

No additional authors.

nav2_behavior_tree

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees for either navigation or autonomy systems. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The nav2_behavior_tree module provides:

  • A C++ template class for easily integrating ROS2 actions and services into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes for navigation or higher-level autonomy applications.

See its Configuration Guide Page for additional parameter descriptions and a list of XML nodes made available in this package. Also review the Nav2 Behavior Tree Explanation pages explaining more context on the default behavior trees and examples provided in this package. A tutorial is also provided to explain how to create a simple BT plugin.

See the Navigation Plugin list for a list of the currently known and available planner plugins.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BtActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root BTCPP_format="4">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}" controller_property="FollowPath"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/docs/3.8/learn-the-basics/BT_basics

CHANGELOG

Wiki Tutorials

This package does not provide any links to tutorials in it's rosindex metadata. You can check on the ROS Wiki Tutorials page for the package.

Launch files

No launch files found

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged nav2_behavior_tree at Robotics Stack Exchange

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Package Summary

Tags No category tags.
Version 0.3.5
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version eloquent-devel
Last Updated 2021-01-04
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

TODO

Additional Links

No additional links.

Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

No additional authors.

nav2_behavior_tree

The nav2_behavior_tree module provides:

  • A C++ template class for integrating ROS2 actions into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes.

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BtActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}" controller_property="FollowPath"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

The nav2_behavior_tree package provides several navigation-specific nodes that are pre-registered and can be included in Behavior Trees.

BT Node Type Description
Backup Action Invokes the BackUp ROS2 action server, which causes the robot to back up to a specific pose. This is used in nav2 Behavior Trees as a recovery behavior. The nav2_recoveries module implements the BackUp action server.
ComputePathToPose Action Invokes the ComputePathToPose ROS2 action server, which is implemented by the nav2_planner module. The server address can be remapped using the server_name input port.
FollowPath Action Invokes the FollowPath ROS2 action server, which is implemented by the controller plugin modules loaded. The server address can be remapped using the server_name input port.
GoalReached Condition Checks the distance to the goal, if the distance to goal is less than the pre-defined threshold, the tree returns SUCCESS, otherwise it returns FAILURE.
IsStuck Condition Determines if the robot is not progressing towards the goal. If the robot is stuck and not progressing, the condition returns SUCCESS, otherwise it returns FAILURE.
NavigateToPose Action Invokes the NavigateToPose ROS2 action server, which is implemented by the bt_navigator module.
RateController Decorator A node that throttles the tick rate for its child. The tick rate can be supplied to the node as a parameter. The node returns RUNNING when it is not ticking its child. Currently, in the navigation stack, the RateController is used to adjust the rate at which the ComputePathToPose and GoalReached nodes are ticked.
RandomCrawl Action This BT action invokes the RandomCrawl ROS2 action server, which is implemented by the nav2_experimental/nav2_rl/nav2_turtlebot3_rl experimental module. The RandomCrawl action server will direct the robot to randomly navigate its environment without hitting any obstacles.
RecoveryNode Control The RecoveryNode is a control flow node with two children. It returns SUCCESS if and only if the first child returns SUCCESS. The second child will be executed only if the first child returns FAILURE. If the second child SUCCEEDS, then the first child will be executed again. The user can specify how many times the recovery actions should be taken before returning FAILURE. In nav2, the RecoveryNode is included in Behavior Trees to implement recovery actions upon failures.
Spin Action Invokes the Spin ROS2 action server, which is implemented by the nav2_recoveries module. This action is using in nav2 Behavior Trees as a recovery behavior.
PipelineSequence Control Ticks the first child till it succeeds, then ticks the first and second children till the second one succeeds. It then ticks the first, second, and third children until the third succeeds, and so on, and so on. If at any time a child returns RUNNING, that doesn’t change the behavior. If at any time a child returns FAILURE, that stops all children and returns FAILURE overall.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/bt_basics/

CHANGELOG

Wiki Tutorials

This package does not provide any links to tutorials in it's rosindex metadata. You can check on the ROS Wiki Tutorials page for the package.

Launch files

No launch files found

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged nav2_behavior_tree at Robotics Stack Exchange

Package Summary

Tags No category tags.
Version 0.2.6
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version dashing-devel
Last Updated 2020-12-28
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

TODO

Additional Links

No additional links.

Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

No additional authors.

nav2_behavior_tree

The nav2_behavior_tree module provides:

  • A C++ template class for integrating ROS2 actions into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes.

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BTActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

The nav2_behavior_tree package provides several navigation-specific nodes that are pre-registered and can be included in Behavior Trees.

BT Node Type Description
Backup Action Invokes the BackUp ROS2 action server, which causes the robot to back up to a specific pose. This is used in nav2 Behavior Trees as a recovery behavior. The nav2_recoveries module implements the BackUp action server.
ComputePathToPose Action Invokes the ComputePathToPose ROS2 action server, which is implemented by the nav2_navfn_planner module.
FollowPath Action Invokes the FollowPath ROS2 action server, which is implemented by the nav2_dwb_controller module.
GoalReached Condition Checks the distance to the goal, if the distance to goal is less than the pre-defined threshold, the tree returns SUCCESS, otherwise it returns FAILURE.
IsStuck Condition Determines if the robot is not progressing towards the goal. If the robot is stuck and not progressing, the condition returns SUCCESS, otherwise it returns FAILURE.
NavigateToPose Action Invokes the NavigateToPose ROS2 action server, which is implemented by the bt_navigator module.
RateController Decorator A node that throttles the tick rate for its child. The tick rate can be supplied to the node as a parameter. The node returns RUNNING when it is not ticking its child. Currently, in the navigation stack, the RateController is used to adjust the rate at which the ComputePathToPose and GoalReached nodes are ticked.
RandomCrawl Action This BT action invokes the RandomCrawl ROS2 action server, which is implemented by the nav2_experimental/nav2_rl/nav2_turtlebot3_rl experimental module. The RandomCrawl action server will direct the robot to randomly navigate its environment without hitting any obstacles.
RecoveryNode Control The RecoveryNode is a control flow node with two children. It returns SUCCESS if and only if the first child returns SUCCESS. The second child will be executed only if the first child returns FAILURE. If the second child SUCCEEDS, then the first child will be executed again. The user can specify how many times the recovery actions should be taken before returning FAILURE. In nav2, the RecoveryNode is included in Behavior Trees to implement recovery actions upon failures.
Spin Action Invokes the Spin ROS2 action server, which is implemented by the nav2_recoveries module. This action is using in nav2 Behavior Trees as a recovery behavior.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/bt_basics/

CHANGELOG

Wiki Tutorials

This package does not provide any links to tutorials in it's rosindex metadata. You can check on the ROS Wiki Tutorials page for the package.

Launch files

No launch files found

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged nav2_behavior_tree at Robotics Stack Exchange

Package Summary

Tags No category tags.
Version 1.0.12
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version galactic
Last Updated 2022-09-15
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

TODO

Additional Links

No additional links.

Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

No additional authors.

nav2_behavior_tree

The nav2_behavior_tree module provides:

  • A C++ template class for integrating ROS2 actions into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes.

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BtActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}" controller_property="FollowPath"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

The nav2_behavior_tree package provides several navigation-specific nodes that are pre-registered and can be included in Behavior Trees.

BT Node Type Description
Backup Action Invokes the BackUp ROS2 action server, which causes the robot to back up to a specific pose. This is used in nav2 Behavior Trees as a recovery behavior. The nav2_recoveries module implements the BackUp action server.
ComputePathToPose Action Invokes the ComputePathToPose ROS2 action server, which is implemented by the nav2_planner module. The server address can be remapped using the server_name input port.
ComputePathThroughPoses Action Invokes the ComputePathThroughPoses ROS2 action server, which is implemented by the nav2_planner module. The server address can be remapped using the server_name input port.
RemovePassedGoals Action Removes goals from a vector of intermediary goal poses which the robot is either approaching or has passed within a tolerance of to prevent replanning to initial points.
FollowPath Action Invokes the FollowPath ROS2 action server, which is implemented by the controller plugin modules loaded. The server address can be remapped using the server_name input port.
GoalReached Condition Checks the distance to the goal, if the distance to goal is less than the pre-defined threshold, the tree returns SUCCESS, otherwise it returns FAILURE.
IsStuck Condition Determines if the robot is not progressing towards the goal. If the robot is stuck and not progressing, the condition returns SUCCESS, otherwise it returns FAILURE.
TransformAvailable Condition Checks if a TF transform is available. Returns failure if it cannot be found. Once found, it will always return success. Useful for initial condition checks.
GoalUpdated Condition Checks if the global navigation goal has changed in the blackboard. Returns failure if the goal is the same, if it changes, it returns success.
IsBatteryLow Condition Checks if battery is low by subscribing to a sensor_msgs/BatteryState topic and checking if battery voltage/percentage is below a specified minimum value.
NavigateToPose Action Invokes the NavigateToPose ROS2 action server, which is implemented by the bt_navigator module.
NavigateThroughPoses Action Invokes the NavigateThroughPoses ROS2 action server, which is implemented by the bt_navigator module.
RateController Decorator A node that throttles the tick rate for its child. The tick rate can be supplied to the node as a parameter. The node returns RUNNING when it is not ticking its child. Currently, in the navigation stack, the RateController is used to adjust the rate at which the ComputePathToPose and GoalReached nodes are ticked.
DistanceController Decorator A node that controls the tick rate for its child based on the distance traveled. The distance to be traveled before replanning can be supplied to the node as a parameter. The node returns RUNNING when it is not ticking its child. Currently, in the navigation stack, the DistanceController is used to adjust the rate at which the ComputePathToPose and GoalReached nodes are ticked.
SpeedController Decorator A node that controls the tick rate for its child based on the current robot speed. This decorator offers the most flexibility as the user can set the minimum/maximum tick rate which is adjusted according to the current robot speed.
SingleTrigger Decorator A node that triggers its child node(s) only a single time. It returns FAILURE in all other ticks.
RecoveryNode Control The RecoveryNode is a control flow node with two children. It returns SUCCESS if and only if the first child returns SUCCESS. The second child will be executed only if the first child returns FAILURE. If the second child SUCCEEDS, then the first child will be executed again. The user can specify how many times the recovery actions should be taken before returning FAILURE. In nav2, the RecoveryNode is included in Behavior Trees to implement recovery actions upon failures.
Spin Action Invokes the Spin ROS2 action server, which is implemented by the nav2_recoveries module. This action is used in nav2 Behavior Trees as a recovery behavior.
PipelineSequence Control Ticks the first child till it succeeds, then ticks the first and second children till the second one succeeds. It then ticks the first, second, and third children until the third succeeds, and so on, and so on. If at any time a child returns RUNNING, that doesn’t change the behavior. If at any time a child returns FAILURE, that stops all children and returns FAILURE overall.
ClearEntireCostmap Action Invokes the ClearEntireCostmap ROS2 service server of costmap_2d_ros. The service address needs to be specified using the service_name input port, typically local_costmap/clear_entirely_local_costmap or global_costmap/clear_entirely_global_costmap. This action is used in nav2 Behavior Trees as a recovery behavior.
ClearCostmapExceptRegion Action Invokes the ClearCostmapExceptRegion ROS2 service server of costmap_2d_ros. It will clear all the costmap apart a square area centered on the robot of side size equal to the reset_distance input port. The service address needs to be specified using the service_name input port, typically local_costmap/clear_except_local_costmap or global_costmap/clear_except_global_costmap. This action is used in nav2 Behavior Trees as a recovery behavior.
ClearCostmapAroundRobot Action Invokes the ClearCostmapAroundRobot ROS2 service server of costmap_2d_ros. It will only clear the costmap on a square area centered on the robot of side size equal to the reset_distance input port. The service address needs to be specified using the service_name input port, typically local_costmap/clear_around_local_costmap or global_costmap/clear_around_global_costmap. This action is used in nav2 Behavior Trees as a recovery behavior.
PlannerSelector Action The PlannerSelector behavior is used to switch the planner that will be used by the planner server. It subscribes to a topic “planner_selector” to get the decision about what planner must be used. It is usually used before of the ComputePathToPoseAction. The selected_planner output port is passed to planner_id input port of the ComputePathToPoseAction.
ControllerSelector Action The ControllerSelector behavior is used to switch the controller that will be used by the controller server. It subscribes to a topic “controller_selector” to get the decision about what controller must be used. It is usually used before of the FollowPath. The selected_controller output port is passed to controller_id input port of the FollowPath.
GoalCheckerSelector Action The GoalCheckerSelector behavior is used to switch the current goal checker of the controller_server. It subscribes to a topic “goal_checker_selector” to get the decision about what goal_checker must be used. It is usually used before of the FollowPath. The selected_goal_checker output port is passed to goal_checker_id input port of the FollowPath.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/bt_basics/

CHANGELOG

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Package Summary

Tags No category tags.
Version 0.4.7
License Apache-2.0
Build type AMENT_CMAKE
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/ros-planning/navigation2.git
VCS Type git
VCS Version foxy-devel
Last Updated 2022-08-31
Dev Status DEVELOPED
CI status No Continuous Integration
Released RELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

TODO

Additional Links

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Maintainers

  • Michael Jeronimo
  • Carlos Orduno
  • Carlos Orduno

Authors

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nav2_behavior_tree

The nav2_behavior_tree module provides:

  • A C++ template class for integrating ROS2 actions into Behavior Trees,
  • Navigation-specific behavior tree nodes, and
  • a generic BehaviorTreeEngine class that simplifies the integration of BT processing into ROS2 nodes.

This module is used by the nav2_bt_navigator to implement a ROS2 node that executes navigation Behavior Trees. The nav2_behavior_tree module uses the Behavior-Tree.CPP library for the core Behavior Tree processing.

The bt_action_node Template and the Behavior Tree Engine

The bt_action_node template allows one to easily integrate a ROS2 action into a BehaviorTree. To do so, one derives from the BtActionNode template, providing the action message type. For example,

#include "nav2_msgs/action/follow_path.hpp"
#include "nav2_behavior_tree/bt_action_node.hpp"

class FollowPathAction : public BtActionNode<nav2_msgs::action::FollowPath>
{
    ...
};

The resulting node must be registered with the factory in the Behavior Tree engine in order to be available for use in Behavior Trees executed by this engine.

BehaviorTreeEngine::BehaviorTreeEngine()
{
    ...

  factory_.registerNodeType<nav2_behavior_tree::FollowPathAction>("FollowPath");

    ...
}

Once a new node is registered with the factory, it is now available to the BehaviorTreeEngine and can be used in Behavior Trees. For example, the following simple XML description of a BT shows the FollowPath node in use:

<root main_tree_to_execute="MainTree">
  <BehaviorTree ID="MainTree">
    <Sequence name="root">
      <ComputePathToPose goal="${goal}"/>
      <FollowPath path="${path}" controller_property="FollowPath"/>
    </Sequence>
  </BehaviorTree>
</root>

The BehaviorTree engine has a run method that accepts an XML description of a BT for execution:

  BtStatus run(
    BT::Blackboard::Ptr & blackboard,
    const std::string & behavior_tree_xml,
    std::function<void()> onLoop,
    std::function<bool()> cancelRequested,
    std::chrono::milliseconds loopTimeout = std::chrono::milliseconds(10));

See the code in the BT Navigator for an example usage of the BehaviorTreeEngine.

The nav2_behavior_tree package provides several navigation-specific nodes that are pre-registered and can be included in Behavior Trees.

BT Node Type Description
Backup Action Invokes the BackUp ROS2 action server, which causes the robot to back up to a specific pose. This is used in nav2 Behavior Trees as a recovery behavior. The nav2_recoveries module implements the BackUp action server.
ComputePathToPose Action Invokes the ComputePathToPose ROS2 action server, which is implemented by the nav2_planner module. The server address can be remapped using the server_name input port.
FollowPath Action Invokes the FollowPath ROS2 action server, which is implemented by the controller plugin modules loaded. The server address can be remapped using the server_name input port.
GoalReached Condition Checks the distance to the goal, if the distance to goal is less than the pre-defined threshold, the tree returns SUCCESS, otherwise it returns FAILURE.
IsStuck Condition Determines if the robot is not progressing towards the goal. If the robot is stuck and not progressing, the condition returns SUCCESS, otherwise it returns FAILURE.
TransformAvailable Condition Checks if a TF transform is available. Returns failure if it cannot be found. Once found, it will always return success. Useful for initial condition checks.
GoalUpdated Condition Checks if the global navigation goal has changed in the blackboard. Returns failure if the goal is the same, if it changes, it returns success.
IsBatteryLow Condition Checks if battery is low by subscribing to a sensor_msgs/BatteryState topic and checking if battery voltage/percentage is below a specified minimum value.
NavigateToPose Action Invokes the NavigateToPose ROS2 action server, which is implemented by the bt_navigator module.
RateController Decorator A node that throttles the tick rate for its child. The tick rate can be supplied to the node as a parameter. The node returns RUNNING when it is not ticking its child. Currently, in the navigation stack, the RateController is used to adjust the rate at which the ComputePathToPose and GoalReached nodes are ticked.
DistanceController Decorator A node that controls the tick rate for its child based on the distance traveled. The distance to be traveled before replanning can be supplied to the node as a parameter. The node returns RUNNING when it is not ticking its child. Currently, in the navigation stack, the DistanceController is used to adjust the rate at which the ComputePathToPose and GoalReached nodes are ticked.
SpeedController Decorator A node that controls the tick rate for its child based on the current robot speed. This decorator offers the most flexibility as the user can set the minimum/maximum tick rate which is adjusted according to the current robot speed.
RecoveryNode Control The RecoveryNode is a control flow node with two children. It returns SUCCESS if and only if the first child returns SUCCESS. The second child will be executed only if the first child returns FAILURE. If the second child SUCCEEDS, then the first child will be executed again. The user can specify how many times the recovery actions should be taken before returning FAILURE. In nav2, the RecoveryNode is included in Behavior Trees to implement recovery actions upon failures.
Spin Action Invokes the Spin ROS2 action server, which is implemented by the nav2_recoveries module. This action is using in nav2 Behavior Trees as a recovery behavior.
PipelineSequence Control Ticks the first child till it succeeds, then ticks the first and second children till the second one succeeds. It then ticks the first, second, and third children until the third succeeds, and so on, and so on. If at any time a child returns RUNNING, that doesn’t change the behavior. If at any time a child returns FAILURE, that stops all children and returns FAILURE overall.

For more information about the behavior tree nodes that are available in the default BehaviorTreeCPP library, see documentation here: https://www.behaviortree.dev/bt_basics/

CHANGELOG

Wiki Tutorials

This package does not provide any links to tutorials in it's rosindex metadata. You can check on the ROS Wiki Tutorials page for the package.

Launch files

No launch files found

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged nav2_behavior_tree at Robotics Stack Exchange

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