nav2_behavior_tree::PipelineSequence Class Reference

Type of sequence node that re-ticks previous children when a child returns running. More...

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

Inheritance diagram for nav2_behavior_tree::PipelineSequence:

Collaboration diagram for nav2_behavior_tree::PipelineSequence:

Public Member Functions
	PipelineSequence (const std::string &name)
	A constructor for nav2_behavior_tree::PipelineSequence. More...
	PipelineSequence (const std::string &name, const BT::NodeConfiguration &config)
	A constructor for nav2_behavior_tree::PipelineSequence. More...
void	halt () override
	The other (optional) override required by a BT action to reset node state.

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...

Protected Attributes
std::size_t	last_child_ticked_ = 0

Detailed Description

Type of sequence node that re-ticks previous children when a child returns running.

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

PipelineSequence | Restart | Tick All Previous Again

Tick All Previous Again means every node up till this one will be reticked. Even if a previous node returns Running, the next node 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

• PipelineSequence returns RUNNING and no other nodes are ticked. | SUCCESS | RUNNING | IDLE | - This time A returns SUCCESS so B gets ticked as well
• PipelineSequence returns RUNNING and C is not ticked yet | RUNNING | SUCCESS | RUNNING | - A gets ticked and returns RUNNING, but since it had previously
• returned SUCCESS, PipelineSequence continues on and ticks B.
• Since B also returns SUCCESS, C gets ticked this time as well. | RUNNING | SUCCESS | SUCCESS | - A is still RUNNING, and B returns SUCCESS again. This time C
• returned SUCCESS, ending the sequence. PipelineSequence
• returns SUCCESS and halts A.

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

Usage in XML: <PipelineSequence>

Definition at line 55 of file pipeline_sequence.hpp.

Constructor & Destructor Documentation

PipelineSequence() [1/2]

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

explicit

A constructor for nav2_behavior_tree::PipelineSequence.

Parameters

name	Name for the XML tag for this node

Definition at line 24 of file pipeline_sequence.cpp.

PipelineSequence() [2/2]

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

A constructor for nav2_behavior_tree::PipelineSequence.

Parameters

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

Definition at line 29 of file pipeline_sequence.cpp.

Member Function Documentation

providedPorts()

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

inlinestatic

Creates list of BT ports.

Returns

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

Definition at line 80 of file pipeline_sequence.hpp.

tick()

BT::NodeStatus nav2_behavior_tree::PipelineSequence::tick ( )

overrideprotected

The main override required by a BT action.

Returns

BT::NodeStatus Status of tick execution

Definition at line 36 of file pipeline_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/pipeline_sequence.hpp
• nav2_behavior_tree/plugins/control/pipeline_sequence.cpp