Flexible and configurable ROS 2 behavior tree executor node. More...

#include <auto_apms_behavior_tree/executor/generic_executor_node.hpp>

Inheritance diagram for GenericTreeExecutorNode:

[legend]

Public Member Functions
	GenericTreeExecutorNode (rclcpp::Node::SharedPtr node_ptr, Options options)
	Constructor using an existing ROS 2 node.

	GenericTreeExecutorNode (const std::string &name, Options options)
	Constructor which creates a new ROS 2 node.

	GenericTreeExecutorNode (const std::string &name)
	Constructor with default executor options.

std::shared_future< ExecutionResult >	startExecution (const std::string &build_request, const std::string &entry_point="", const core::NodeManifest &node_manifest={})
	Start the behavior tree specified by a particular build request.

ExecutorParameters	getExecutorParameters () const
	Get a copy of the current executor parameters.

std::map< std::string, rclcpp::ParameterValue >	getParameterValuesWithPrefix (const std::string &prefix)
	Assemble all parameters of this node that have a specific prefix.

bool	updateScriptingEnumsWithParameterValues (const std::map< std::string, rclcpp::ParameterValue > &value_map, bool simulate=false)
	Update the internal buffer of scripting enums.

bool	updateGlobalBlackboardWithParameterValues (const std::map< std::string, rclcpp::ParameterValue > &value_map, bool simulate=false)
	Update the global blackboard using parameter values.

void	loadBuildHandler (const std::string &name)
	Load a particular behavior tree build handler plugin.

TreeConstructor	makeTreeConstructor (const std::string &build_request, const std::string &entry_point="", const core::NodeManifest &node_manifest={})
	Create a callback that builds a behavior tree according to a specific request.

core::TreeBuilder::SharedPtr	createTreeBuilder ()
	Create a tree builder for building the behavior tree.

virtual bool	clearGlobalBlackboard () override
	Reset the global blackboard and clear all entries.

std::shared_future< ExecutionResult >	startExecution (TreeConstructor make_tree, double tick_rate_sec=0.1, int groot2_port=-1)
	Start a behavior tree that is built using a callback.

template<typename TimeRepT = int64_t, typename TimeT = std::milli>
std::shared_future< ExecutionResult >	startExecution (TreeConstructor make_tree, const std::chrono::duration< TimeRepT, TimeT > &tick_rate, int groot2_port=-1)
	Start a behavior tree that is built using a callback.

Public Member Functions inherited from TreeExecutorBase
	TreeExecutorBase (rclcpp::Node::SharedPtr node_ptr, rclcpp::CallbackGroup::SharedPtr tree_node_callback_group_ptr=nullptr)
	Constructor.

std::shared_future< ExecutionResult >	startExecution (TreeConstructor make_tree, double tick_rate_sec=0.1, int groot2_port=-1)
	Start a behavior tree that is built using a callback.

template<typename TimeRepT = int64_t, typename TimeT = std::milli>
std::shared_future< ExecutionResult >	startExecution (TreeConstructor make_tree, const std::chrono::duration< TimeRepT, TimeT > &tick_rate, int groot2_port=-1)
	Start a behavior tree that is built using a callback.

void	setControlCommand (ControlCommand cmd)
	Set the command that handles the control flow of the execution routine.

bool	isBusy ()
	Determine whether this executor is currently executing a behavior tree.

ExecutionState	getExecutionState ()
	Get a status code indicating the current state of execution.

std::string	getTreeName ()
	Get the name of the tree that is currently executing.

TreeBlackboardSharedPtr	getGlobalBlackboardPtr ()
	Get a shared pointer to the global blackboard instance.

TreeStateObserver &	getStateObserver ()
	Get a reference to the current behavior tree state observer.

rclcpp::Node::SharedPtr	getNodePtr ()
	Get a shared pointer to the parent ROS 2 node.

rclcpp::node_interfaces::NodeBaseInterface::SharedPtr	get_node_base_interface ()
	Get the node's base interface. Is required to be able to register derived classes as ROS2 components.

rclcpp::CallbackGroup::SharedPtr	getTreeNodeWaitablesCallbackGroupPtr ()
	Get the callback group used for all waitables registered by behavior tree nodes.

rclcpp::executors::SingleThreadedExecutor::SharedPtr	getTreeNodeWaitablesExecutorPtr ()
	Get the ROS 2 executor instance used for spinning waitables registered by behavior tree nodes.

Static Public Member Functions
static std::string	stripPrefixFromParameterName (const std::string &prefix, const std::string &param_name)
	Get the name of a parameter without its prefix.

Static Public Attributes
static const std::string	PARAM_VALUE_NO_BUILD_HANDLER = "none"
	Value indicating that no build handler is loaded.

Protected Member Functions
virtual void	preBuild (core::TreeBuilder &builder, const std::string &build_request, const std::string &entry_point, const core::NodeManifest &node_manifest, TreeBlackboard &bb)
	Callback invoked before building the behavior tree.

virtual void	postBuild (Tree &tree)
	Callback invoked after the behavior tree has been instantiated.

Additional Inherited Members
Public Types inherited from TreeExecutorBase
enum class	ExecutionState : uint8_t { IDLE , STARTING , RUNNING , PAUSED , HALTED }
	Enum representing possible behavior tree execution states. More...

enum class	ControlCommand : uint8_t { RUN , PAUSE , HALT , TERMINATE }
	Enum representing possible commands for controlling the behavior tree execution routine. More...

enum class	TreeExitBehavior : uint8_t { TERMINATE , RESTART }
	Enum representing possible options for what to do when a behavior tree is completed. More...

enum class	ExecutionResult : uint8_t { TREE_SUCCEEDED , TREE_FAILED , TERMINATED_PREMATURELY , ERROR }
	Enum representing possible behavior tree execution results. More...

Protected Attributes inherited from TreeExecutorBase
rclcpp::Node::SharedPtr	node_ptr_
	Shared pointer to the parent ROS 2 node.

const rclcpp::Logger	logger_
	Logger associated with the parent ROS 2 node.

Detailed Description

Flexible and configurable ROS 2 behavior tree executor node.

This executor extends TreeExecutorBase with configurable support for:

Build handler management (loading and switching build handlers)
CommandTreeExecutor action interface (pause, resume, halt, terminate)
Parameter/blackboard synchronization
Scripting enum parameters

Derived classes can trigger the behavior tree execution by calling GenericTreeExecutorNode::startExecution with a build request or a TreeConstructor directly.

Definition at line 59 of file generic_executor_node.hpp.

Constructor & Destructor Documentation

◆ GenericTreeExecutorNode() [1/3]

GenericTreeExecutorNode	(	rclcpp::Node::SharedPtr	node_ptr,
		Options	options )

Constructor using an existing ROS 2 node.

This allows embedding the executor inside another node (e.g. via composition) without creating a separate rclcpp::Node instance.

Parameters

node_ptr	Shared pointer to the ROS 2 node to use.
options	Executor options.

Definition at line 31 of file generic_executor_node.cpp.

◆ GenericTreeExecutorNode() [2/3]

GenericTreeExecutorNode	(	const std::string &	name,
		Options	options )

Constructor which creates a new ROS 2 node.

Parameters

name	Name of the `rclcpp::Node`.
options	Executor options.

Definition at line 170 of file generic_executor_node.cpp.

◆ GenericTreeExecutorNode() [3/3]

GenericTreeExecutorNode ( const std::string & name )

Constructor with default executor options.

Parameters

name	Name of the `rclcpp::Node`.

Definition at line 175 of file generic_executor_node.cpp.

Member Function Documentation

◆ startExecution() [1/3]

std::shared_future< GenericTreeExecutorNode::ExecutionResult > startExecution	(	const std::string &	build_request,
		const std::string &	entry_point = "",
		const core::NodeManifest &	node_manifest = {} )

Start the behavior tree specified by a particular build request.

Parameters

build_request	Behavior build request for creating the behavior.
entry_point	Single point of entry for behavior execution.
node_manifest	Behavior tree node manifest to be loaded for behavior execution.

Returns: Shared future that completes once executing the tree is finished or an error occurs.

Definition at line 185 of file generic_executor_node.cpp.

◆ preBuild()

void preBuild	(	core::TreeBuilder &	builder,
		const std::string &	build_request,
		const std::string &	entry_point,
		const core::NodeManifest &	node_manifest,
		TreeBlackboard &	bb )

protectedvirtual

Callback invoked before building the behavior tree.

Note: This hook is only used in the TreeConstructor returned by GenericTreeExecutorNode::makeTreeConstructor. Remember that if you pass a custom TreeConstructor directly to TreeExecutorBase::startExecution, you bypass this hook if you don't explicitly include it.

Parameters

builder	Tree builder to be configured.
build_request	Behavior build request.
entry_point	Single point of entry for behavior execution.
node_manifest	Behavior tree node manifest.
bb	Local blackboard of the tree being created.

Definition at line 177 of file generic_executor_node.cpp.

◆ postBuild()

void postBuild ( Tree & tree )

protectedvirtual

Callback invoked after the behavior tree has been instantiated.

Note: This hook is only used in the TreeConstructor returned by GenericTreeExecutorNode::makeTreeConstructor. Remember that if you pass a custom TreeConstructor directly to TreeExecutorBase::startExecution, you bypass this hook if you don't explicitly include it.

Parameters

tree	Behavior tree that has been created and is about to be executed.

Definition at line 183 of file generic_executor_node.cpp.

◆ getExecutorParameters()

GenericTreeExecutorNode::ExecutorParameters getExecutorParameters ( ) const

Get a copy of the current executor parameters.

Returns: Current executor parameters.

Definition at line 252 of file generic_executor_node.cpp.

◆ getParameterValuesWithPrefix()

std::map< std::string, rclcpp::ParameterValue > getParameterValuesWithPrefix ( const std::string & prefix )

Assemble all parameters of this node that have a specific prefix.

Parameters

prefix Only consider parameters that have this prefix in their names.

Returns: Map of parameter names and their respective values.

Definition at line 257 of file generic_executor_node.cpp.

◆ stripPrefixFromParameterName()

std::string stripPrefixFromParameterName	(	const std::string &	prefix,
		const std::string &	param_name )

static

Get the name of a parameter without its prefix.

Parameters

prefix	Prefix to remove from `param_name`.
param_name	Name of the parameter with its prefix.

Returns: Name of the parameter without its prefix.

Definition at line 270 of file generic_executor_node.cpp.

◆ updateScriptingEnumsWithParameterValues()

bool updateScriptingEnumsWithParameterValues	(	const std::map< std::string, rclcpp::ParameterValue > &	value_map,
		bool	simulate = false )

Update the internal buffer of scripting enums.

Parameters

value_map	Map of parameter names and their respective values.
simulate	Set to `true` to only validate.

Returns: true if updating is possible.

Definition at line 278 of file generic_executor_node.cpp.

◆ updateGlobalBlackboardWithParameterValues()

bool updateGlobalBlackboardWithParameterValues	(	const std::map< std::string, rclcpp::ParameterValue > &	value_map,
		bool	simulate = false )

Update the global blackboard using parameter values.

Parameters

value_map	Map of parameter names and their respective values.
simulate	Set to `true` to only validate.

Returns: true if updating is possible.

Definition at line 313 of file generic_executor_node.cpp.

◆ loadBuildHandler()

void loadBuildHandler ( const std::string & name )

Load a particular behavior tree build handler plugin.

Parameters

name	Fully qualified name of the build handler class. Set to `"none"` to unload.

Definition at line 349 of file generic_executor_node.cpp.

◆ makeTreeConstructor()

TreeConstructor makeTreeConstructor	(	const std::string &	build_request,
		const std::string &	entry_point = "",
		const core::NodeManifest &	node_manifest = {} )

Create a callback that builds a behavior tree according to a specific request.

Parameters

build_request	Request that specifies how to build the behavior tree.
entry_point	Single point of entry for behavior execution.
node_manifest	Behavior tree node manifest.

Returns: Callback for creating the behavior tree.

Definition at line 378 of file generic_executor_node.cpp.

◆ createTreeBuilder()

core::TreeBuilder::SharedPtr createTreeBuilder ( )

Create a tree builder for building the behavior tree.

Returns: Shared pointer to the created tree builder.

Definition at line 418 of file generic_executor_node.cpp.

◆ clearGlobalBlackboard()

bool clearGlobalBlackboard ( )

overridevirtual

Reset the global blackboard and clear all entries.

Returns: true if blackboard was cleared, false if executor is not idle.

Reimplemented from TreeExecutorBase.

Definition at line 425 of file generic_executor_node.cpp.

◆ startExecution() [2/3]

std::shared_future< TreeExecutorBase::ExecutionResult > startExecution	(	TreeConstructor	make_tree,
		double	tick_rate_sec = 0.1,
		int	groot2_port = -1 )

Start a behavior tree that is built using a callback.

Executing the behavior tree is achieved by regularly invoking the internal routine that ticks the behavior tree created using make_tree. This requires to register a timer with the associated ROS 2 node. Consequently, the behavior tree is executed asynchronously. The user is provided a shared future object that allows to check whether the execution finished. Once this future completes, the execution result can be evaluated.

Parameters

make_tree	Callback that creates a `BT::Tree` object which will be ticked to execute the tree.
tick_rate_sec	Behavior tree tick rate in seconds (1 tick every `tick_rate_sec` seconds) i.e. the interval of the timer that regularly invokes the execution routine.
groot2_port	Port number used for introspection and debugging with Groot2. `-1` means that no `BT::Groot2Publisher` will be installed.

Returns: Shared future that completes once executing the tree is finished or an error occurs. In that case, it is assigned an execution result code.

Definition at line 116 of file executor_base.cpp.

◆ startExecution() [3/3]

template<typename TimeRepT = int64_t, typename TimeT = std::milli>

std::shared_future< TreeExecutorBase::ExecutionResult > startExecution	(	TreeConstructor	make_tree,
		const std::chrono::duration< TimeRepT, TimeT > &	tick_rate,
		int	groot2_port = -1 )

inline

Start a behavior tree that is built using a callback.

Executing the behavior tree is achieved by regularly invoking the internal routine that ticks the behavior tree created using make_tree. This requires to register a timer with the associated ROS 2 node. Consequently, the behavior tree is executed asynchronously. The user is provided a shared future object that allows to check whether the execution finished. Once this future completes, the execution result can be evaluated.

Parameters

make_tree	Callback that creates a `BT::Tree` object which will be ticked to execute the tree.
tick_rate	Behavior tree tick rate i.e. the interval of the timer that regularly invokes the execution routine.
groot2_port	Port number used for introspection and debugging with Groot2. `-1` means that no `BT::Groot2Publisher` will be installed.

Returns: Shared future that completes once executing the tree is finished or an error occurs. In that case, it is assigned an execution result code.

Definition at line 135 of file executor_base.hpp.

Member Data Documentation

◆ PARAM_VALUE_NO_BUILD_HANDLER

const std::string PARAM_VALUE_NO_BUILD_HANDLER = "none"

inlinestatic

Value indicating that no build handler is loaded.

Definition at line 71 of file generic_executor_node.hpp.

The documentation for this class was generated from the following files:

auto_apms_behavior_tree/include/auto_apms_behavior_tree/executor/generic_executor_node.hpp
auto_apms_behavior_tree/src/executor/generic_executor_node.cpp

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ GenericTreeExecutorNode() [1/3]

◆ GenericTreeExecutorNode() [2/3]

◆ GenericTreeExecutorNode() [3/3]

Member Function Documentation

◆ startExecution() [1/3]

◆ preBuild()

◆ postBuild()

◆ getExecutorParameters()

◆ getParameterValuesWithPrefix()

◆ stripPrefixFromParameterName()

◆ updateScriptingEnumsWithParameterValues()

◆ updateGlobalBlackboardWithParameterValues()

◆ loadBuildHandler()

◆ makeTreeConstructor()

◆ createTreeBuilder()

◆ clearGlobalBlackboard()

◆ startExecution() [2/3]

◆ startExecution() [3/3]

Member Data Documentation

◆ PARAM_VALUE_NO_BUILD_HANDLER