# BT Navigator

The BT Navigator (Behavior Tree Navigator) module implements the NavigateToPose and NavigateThroughPoses task interfaces. It is a [Behavior Tree](https://github.com/BehaviorTree/BehaviorTree.CPP/blob/master/docs/BT_basics.md)-based implementation of navigation that is intended to allow for flexibility in the navigation task and provide a way to easily specify complex robot behaviors.

See its [Configuration Guide Page](https://docs.nav2.org/configuration/packages/configuring-bt-navigator.html) for additional parameter descriptions, as well as the [Nav2 Behavior Tree Explanation](https://docs.nav2.org/behavior_trees/index.html) pages explaining more context on the default behavior trees and examples provided in this package.

## Overview

The BT Navigator receives a goal pose and navigates the robot to the specified destination(s). To do so, the module reads an XML description of the Behavior Tree from a file, as specified by a Node parameter, and passes that to a generic [BehaviorTreeEngine class](../nav2_behavior_tree/include/nav2_behavior_tree/behavior_tree_engine.hpp) which uses the [Behavior-Tree.CPP library](https://github.com/BehaviorTree/BehaviorTree.CPP) to dynamically create and execute the BT. The BT XML can also be specified on a per-task basis so that your robot may have many different types of navigation or autonomy behaviors on a per-task basis.