nav2_behavior_tree::NonblockingSequence Class Reference

Type of sequence node that keeps tickinng through all the children until all children return SUCCESS. More...

#include <nav2_behavior_tree/include/nav2_behavior_tree/plugins/control/nonblocking_sequence.hpp>

Inheritance diagram for nav2_behavior_tree::NonblockingSequence:

Collaboration diagram for nav2_behavior_tree::NonblockingSequence:

Public Member Functions
	NonblockingSequence (const std::string &name)
	A constructor for nav2_behavior_tree::NonblockingSequence. More...
	NonblockingSequence (const std::string &name, const BT::NodeConfiguration &config)
	A constructor for nav2_behavior_tree::NonblockingSequence. More...

Static Public Member Functions
static BT::PortsList	providedPorts ()
	Creates list of BT ports. More...

Protected Member Functions
BT::NodeStatus	tick () override
	The main override required by a BT action. More...

Detailed Description

Type of sequence node that keeps tickinng through all the children until all children return SUCCESS.

Type of Control Node | Child Returns Failure | Child Returns Running

NonblockingSequence | Restart | Continue tickng next child

Continue ticking next child means every node after the running node will be ticked. Even if a previous node returns Running or Success, the subsequent nodes will be reticked.

As an example, let's say this node has 3 children: A, B and C. At the start, they are all IDLE.

| A | B | C |

| IDLE | IDLE | IDLE | | RUNNING | IDLE | IDLE | - at first A gets ticked. Assume it returns RUNNING

• NonblockingSequence returns RUNNING and continues to the next
• node. | RUNNING | RUNNING | RUNNING | - Eventually all nodes will be in the running state and
• NonblockingSequence returns RUNNING | SUCCESS | RUNNING | SUCCESS | - Even in a configuration where there are multiple nodes
• returning SUCCESS, NonblockingSequence continues on ticking all.
• nodes each time it is ticked and returns RUNNING. Note that even
• if a node returns SUCCESS, on the next tick, it will attempt to
• restart the node. This is too ensure that successful nodes do
• not latch a stale state while waiting for another long running
• node to be complete | SUCCESS | SUCCESS | SUCCESS | - If all child nodes return SUCCESS the NonblockingSequence
• returns SUCCESS

If any children at any time had returned FAILURE. NonblockingSequence would have returned FAILURE and halted all children, ending the sequence.

Usage in XML: <NonblockingSequence>

Definition at line 60 of file nonblocking_sequence.hpp.

Constructor & Destructor Documentation

NonblockingSequence() [1/2]

nav2_behavior_tree::NonblockingSequence::NonblockingSequence ( const std::string &  name )

explicit

A constructor for nav2_behavior_tree::NonblockingSequence.

Parameters

name	Name for the XML tag for this node

Definition at line 24 of file nonblocking_sequence.cpp.

NonblockingSequence() [2/2]

nav2_behavior_tree::NonblockingSequence::NonblockingSequence	(	const std::string &	name,
		const BT::NodeConfiguration &	config
	)

A constructor for nav2_behavior_tree::NonblockingSequence.

Parameters

name	Name for the XML tag for this node
config	BT node configuration

Definition at line 29 of file nonblocking_sequence.cpp.

Member Function Documentation

providedPorts()

static BT::PortsList nav2_behavior_tree::NonblockingSequence::providedPorts ( )

inlinestatic

Creates list of BT ports.

Returns

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

Definition at line 80 of file nonblocking_sequence.hpp.

tick()

BT::NodeStatus nav2_behavior_tree::NonblockingSequence::tick ( )

overrideprotected

The main override required by a BT action.

Returns

BT::NodeStatus Status of tick execution

Definition at line 36 of file nonblocking_sequence.cpp.

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

• nav2_behavior_tree/include/nav2_behavior_tree/plugins/control/nonblocking_sequence.hpp
• nav2_behavior_tree/plugins/control/nonblocking_sequence.cpp