Template Class BtServiceNode

Inheritance Relationships

Base Type

  • public BT::ActionNodeBase

Class Documentation

template<class ServiceT>
class BtServiceNode : public BT::ActionNodeBase

Abstract class representing a service based BT node.

Note

This is an Asynchronous (long-running) node which may return a RUNNING state while executing. It will re-initialize when halted.

Template Parameters:

ServiceT – Type of service

Public Functions

inline BtServiceNode(const std::string &service_node_name, const BT::NodeConfiguration &conf, const std::string &service_name = "")

A nav2_behavior_tree::BtServiceNode constructor.

Parameters:

  • service_node_name – BT node name

  • conf – BT node configuration

  • service_name – Optional service name this node creates a client for instead of from input port

BtServiceNode() = delete
inline virtual ~BtServiceNode()
inline void initialize()

Function to read parameters and initialize class variables.

inline void createROSInterfaces()

Function to create ROS interfaces.

inline BT::NodeStatus tick() override

The main override required by a BT service.

Returns:

BT::NodeStatus Status of tick execution

inline void halt() override

The other (optional) override required by a BT service.

inline virtual void on_tick()

Function to perform some user-defined operation on tick Fill in service request with information if necessary.

inline virtual BT::NodeStatus on_completion(std::shared_ptr<typename ServiceT::Response>)

Function to perform some user-defined operation upon successful completion of the service. Could put a value on the blackboard.

Parameters:

response – can be used to get the result of the service call in the BT Node.

Returns:

BT::NodeStatus Returns SUCCESS by default, user may override to return another value

inline virtual BT::NodeStatus check_future()

Check the future and decide the status of BT.

Returns:

BT::NodeStatus SUCCESS if future complete before timeout, FAILURE otherwise

inline virtual void on_wait_for_result()

Function to perform some user-defined operation after a timeout waiting for a result that hasn’t been received yet.

Public Static Functions

static inline BT::PortsList providedBasicPorts(BT::PortsList addition)

Any subclass of BtServiceNode that accepts parameters must provide a providedPorts method and call providedBasicPorts in it.

Parameters:

addition – Additional ports to add to BT port list

Returns:

BT::PortsList Containing basic ports along with node-specific ports

static inline BT::PortsList providedPorts()

Creates list of BT ports.

Returns:

BT::PortsList Containing basic ports along with node-specific ports

Protected Functions

inline void increment_recovery_count()

Function to increment recovery count on blackboard if this node wraps a recovery.

Protected Attributes

std::string service_name_
std::string service_node_name_
rclcpp::Client<ServiceT>::SharedPtr service_client_
std::shared_ptr<typename ServiceT::Request> request_
rclcpp_lifecycle::LifecycleNode::SharedPtr node_
rclcpp::CallbackGroup::SharedPtr callback_group_ = {nullptr}
rclcpp::executors::SingleThreadedExecutor::SharedPtr callback_group_executor_
std::chrono::milliseconds server_timeout_
std::chrono::milliseconds max_timeout_
std::chrono::milliseconds wait_for_service_timeout_
std::shared_future<typename ServiceT::Response::SharedPtr> future_result_
bool request_sent_ = {false}
rclcpp::Time sent_time_
bool should_send_request_