Navigation Plugins¶
There are a number of plugin interfaces for users to create their own custom applications or algorithms with. Namely, the costmap layer, planner, controller, behavior tree, and recovery plugins. A list of all known plugins are listed here below for ROS 2 Navigation. If you know of a plugin, or you have created a new plugin, please consider submitting a pull request with that information.
This file can be found and editted under sphinx_docs/plugins/index.rst.
For tutorials on creating your own plugins, please see Writing a New Costmap2D Plugin, Writing a New Behavior Tree Plugin, Writing a New Controller Plugin, Writing a New Planner Plugin, or Writing a New Recovery Plugin.
Costmap Layers¶
| Plugin Name | Creator | Description |
|---|---|---|
| Voxel Layer | Eitan Marder-Eppstein | Maintains persistant 3D voxel layer using depth and laser sensor readings and raycasting to clear free space |
| Range Layer | David Lu | Uses a probabalistic model to put data from sensors that publish range msgs on the costmap |
| Static Layer | Eitan Marder-Eppstein | Gets static map and loads
occupancy information into
costmap |
| Inflation Layer | Eitan Marder-Eppstein | Inflates lethal obstacles in costmap with exponential decay |
| Obstacle Layer | Eitan Marder-Eppstein | Maintains persistent 2D costmap from 2D laser scans with raycasting to clear free space |
| Spatio-Temporal Voxel Layer | Steve Macenski | Maintains temporal 3D sparse volumetric voxel grid with decay through sensor models |
| Non-Persistent Voxel Layer | Steve Macenski | Maintains 3D occupancy grid consisting only of the most sets of measurements |
Costmap Filters¶
| Plugin Name | Creator | Description |
|---|---|---|
| Keepout Filter | Alexey Merzlyakov | Maintains keep-out/safety zones and preferred lanes for moving |
| Speed Filter | Alexey Merzlyakov | Limits maximum velocity of robot in speed restriction areas |
Controllers¶
| Plugin Name | Creator | Description | Drivetrain support |
|---|---|---|---|
| DWB Controller | David Lu!! | A highly configurable DWA implementation with plugin interfaces | Differential, Omnidirectional, Legged |
| TEB Controller | Christoph Rösmann | A MPC-like controller suitable for ackermann, differential, and holonomic robots. | Ackermann, Legged, Omnidirectional, Differential |
| Regulated Pure Pursuit | Steve Macenski | A service / industrial robot variation on the pure pursuit algorithm with adaptive features. | Ackermann, Legged, Differential |
| Rotation Shim Controller | Steve Macenski | A “shim” controller to rotate to path heading before passing to main controller for tracking. | Differential, Omni, model rotate in place |
Planners¶
| Plugin Name | Creator | Description | Drivetrain support |
|---|---|---|---|
| NavFn Planner | Eitan Marder-Eppstein & Kurt Konolige | A navigation function using A* or Dijkstras expansion, assumes 2D holonomic particle | Differential, Omnidirectional, Legged |
|
Steve Macenski | A SE2 Hybrid-A* implementation using either Dubin or Reeds-shepp motion models with smoother and multi-resolution query. Cars, car-like, and ackermann vehicles. Kinematically feasible. | Ackermann, Differential, Omnidirectional, Legged |
| SmacPlanner2D | Steve Macenski | A 2D A* implementation Using either 4 or 8 connected neighborhoods with smoother and multi-resolution query | Differential, Omnidirectional, Legged |
| SmacPlannerLattice | Steve Macenski | An implementation of State Lattice Planner using pre-generated minimum control sets for kinematically feasible planning with any type of vehicle imaginable. Includes generator script for Ackermann, diff, omni, and legged robots. | Differential, Omnidirectional, Ackermann, Legged, Arbitrary / Custom |
| ThetaStarPlanner | Anshumaan Singh | An implementaion of Theta* using either 4 or 8 connected neighborhoods, assumes the robot as a 2D holonomic particle | Differential, Omnidirectional |
Recoveries¶
| Plugin Name | Creator | Description |
|---|---|---|
| Clear Costmap | Eitan Marder-Eppstein | A service to clear the given costmap in case of incorrect perception or robot is stuck |
| Spin | Steve Macenski | Rotate recovery of configurable angles to clear out free space and nudge robot out of potential local failures |
| Back Up | Brian Wilcox | Back up recovery of configurable distance to back out of a situation where the robot is stuck |
| Wait | Steve Macenski | Wait recovery with configurable time to wait in case of time based obstacle like human traffic or getting more sensor data |
Waypoint Task Executors¶
| Plugin Name | Creator | Description |
|---|---|---|
| WaitAtWaypoint | Fetullah Atas | A plugin to execute a wait behavior on waypoint arrivals. |
| PhotoAtWaypoint | Fetullah Atas | A plugin to take and save photos to specified directory on waypoint arrivals. |
| InputAtWaypoint | Steve Macenski | A plugin to wait for user input before moving onto the next waypoint. |
Goal Checkers¶
| Plugin Name | Creator | Description |
|---|---|---|
| SimpleGoalChecker | David Lu!! | A plugin check whether robot is within translational distance and rotational distance of goal. |
| StoppedGoalChecker | David Lu!! | A plugin check whether robot is within translational distance , rotational distance of goal, and velocity threshold. |
Progress Checkers¶
| Plugin Name | Creator | Description |
|---|---|---|
| SimpleProgressChecker | David Lu!! | A plugin to check whether the robot was able to move a minimum distance in a given time to make progress towards a goal |
Behavior Tree Nodes¶
| Action Plugin Name | Creator | Description |
|---|---|---|
| Back Up Action | Michael Jeronimo | Calls backup recovery action |
| Clear Entire Costmap Service | Carl Delsey | Calls clear entire costmap service |
| Clear Costmap Except Region Service | Guillaume Doisy | Calls clear costmap except region service |
| Clear Costmap Around Robot Service | Guillaume Doisy | Calls clear costmap around robot service |
| Compute Path to Pose Action | Michael Jeronimo | Calls Nav2 planner server |
| Follow Path Action | Michael Jeronimo | Calls Nav2 controller server |
| Navigate to Pose Action | Michael Jeronimo | BT Node for other BehaviorTree.CPP BTs to call Navigation2 as a subtree action |
| Reinitalize Global Localization Service | Carl Delsey | Reinitialize AMCL to a new pose |
| Spin Action | Carl Delsey | Calls spin recovery action |
| Wait Action | Steve Macenski | Calls wait recovery action |
| Truncate Path | Francisco Martín | Modifies a path making it shorter |
| Planner Selector | Pablo Iñigo Blasco | Selects the global planner based on a topic input, otherwises uses a default planner id |
| Controller Selector | Pablo Iñigo Blasco | Selects the controller based on a topic input, otherwises uses a default controller id |
| Goal Checker Selector | Pablo Iñigo Blasco | Selects the goal checker based on a topic input, otherwises uses a default goal checker id |
| Navigate Through Poses | Steve Macenski | BT Node for other BehaviorTree.CPP BTs to call Nav2’s NavThroughPoses action |
| Remove Passed Goals | Steve Macenski | Removes goal poses passed or within a tolerance for culling old viapoints from path re-planning |
| Compute Path Through Poses | Steve Macenski | Computes a path through a set of poses rather than a single end goal pose using the planner plugin specified |
| Condition Plugin Name | Creator | Description |
|---|---|---|
| Goal Reached Condition | Carl Delsey | Checks if goal is reached within tol. |
| Goal Updated Condition | Aitor Miguel Blanco | Checks if goal is preempted. |
| Initial Pose received Condition | Carl Delsey | Checks if initial pose has been set |
| Is Stuck Condition | Michael Jeronimo | Checks if robot is making progress or stuck |
| Transform Available Condition | Steve Macenski | Checks if a TF transformation is available. When succeeds returns success for subsequent calls. |
| Distance Traveled Condition | Sarthak Mittal | Checks is robot has traveled a given distance. |
| Time Expired Condition | Sarthak Mittal | Checks if a given time period has passed. |
| Is Battery Low Condition | Sarthak Mittal | Checks if battery percentage is below a specified value. |
| Decorator Plugin Name | Creator | Description |
|---|---|---|
| Rate Controller | Michael Jeronimo | Throttles child node to a given rate |
| Distance Controller | Sarthak Mittal | Ticks child node based on the distance traveled by the robot |
| Speed Controller | Sarthak Mittal | Throttles child node to a rate based on current robot speed. |
| Goal Updater | Francisco Martín | Updates the goal received via topic subscription. |
| Single Trigger | Steve Macenski | Triggers nodes/subtrees below only a single time per BT run. |
| Control Plugin Name | Creator | Description |
|---|---|---|
| Pipeline Sequence | Carl Delsey | A variant of a sequence node that will re-tick previous children even if another child is running |
| Recovery | Carl Delsey | Node must contain 2 children and returns success if first succeeds. If first fails, the second will be ticked. If successful, it will retry the first and then return its value |
| Round Robin | Mohammad Haghighipanah | Will tick i th child until
a result and move on to i+1 |