Humble to Iron

Moving from ROS 2 Humble to Iron, a number of stability improvements were added that we will not specifically address here.

Added Collision Monitor

PR 2982 adds new safety layer operating independently of Nav2 stack which ensures the robot to control the collisions with near obstacles, obtained from different sensors (LaserScan, PointCloud, IR, Sonars, etc…). See Collision Monitor for more details. It is not included in the default bringup batteries included from nav2_bringup.

Removed use_sim_time from yaml

PR #3131 makes it possible to set the use_sim_time parameter from the launch file for multiple nodes instead of individually via the yaml files. If using the Nav2 launch files, you can optionally remove the use_sim_time parameter from your yaml files and set it via a launch argument.

Run-time Speed up of Smac Planner

The core data structure of the graph implementation in the Smac Planner framework was swapped out in PR 3201 to using a specialized unordered map implementation. This speeds up the planner by 10% on trivial requests and reports up to 30% on complex plans that involve numerous rehashings.

Recursive Refinement of Smac and Simple Smoothers

The number of recursive refinements for the Simple and Smac Planner Smoothers have been exposed under the refinement_num parameter. Previous behavior had this hardcoded if do_refinement = True to 4. Now, default is 2 to help decrease out-of-the-box over smoothing reducing in paths closer to collision than probably ideal, but old behavior can be achieved by changing this to 4.

Simple Commander Python API

PR 3159 and follow-up PRs add in Costmap API in Python3 simple commander to receive OccupancyGrid messages from Nav2 and be able to work with them natively in Python3, analog to the C++ Costmap API. It also includes a line iterator and collision checking object to perform footprint or other collision checking in Python3. See the Simple Commander API for more details.

Smac Planner Start Pose Included in Path

PR 3168 adds the starting pose to the Smac Planners that was previously excluded during backtracing.

Parameterizable Collision Checking in RPP

PR 3204 adds makes collision checking for RPP optional (default on).

Expaned Planner Benchmark Tests

PR 3218 adds launch files and updated scripts for performing objective random planning tests across the planners in Nav2 for benchmarking and metric computation.

Smac Planner Path Tolerances

PR 3219 adds path tolerances to Hybrid-A* and State Lattice planners to return approximate paths if exact paths cannot be found, within a configurable tolerance aroun the goal pose.

costmap_2d_node default constructor

PR #3222 changes the constructor used by the standalone costmap node. The new constructor does not set a name and namespace internally so it can be set via the launch file.

Feedback for Navigation Failures

PR #3146 updates the global planners to throw exceptions on planning failures. These exceptions get reported back to the planner server which in turn places a error code on the Behavior Tree Navigator’s blackboard for use in contextual error handling in the autonomy application.

The following errors codes are supported (with more to come as necessary): Unknown, TF Error, Start or Goal Outside of Map, Start or Goal Occupied, Timeout, or No Valid Path Found.

PR #3248 updates the compute path through poses action to report planning failures. These exceptions get reported back to the planner server which in turn places a error code on the Behavior Tree Navigator’s blackboard for use in contextual error handling in the autonomy application.

The following errors codes are supported (with more to come as necessary): Unknown, TF Error, Start or Goal Outside of Map, Start or Goal Occupied, Timeout, No Valid Path Found and No Waypoints given.

PR #3227 updates the controllers to throw exceptions on failures. These exceptions get reported back to the controller server which in turn places a error code on the Behavior Tree Navigatior’s blackboard for use in contextual error handling in the autonomy application.

The following error codes are supported (with more to come as necessary): Unknown, TF Error, Invalid Path, Patience Exceeded, Failed To Make Progress, or No Valid Control.

Costmap Filters

Costmap Filters now are have an ability to be enabled/disabled in run-time by calling toggle_filter service for appropriate filter (PR #3229).

Added new binary flip filter, allowing e.g. to turn off camera in sensitive areas, turn on headlights/leds/other safety things or switch operating mode when robot is inside marked on mask areas (PR #3228).

Savitzky-Golay Smoother

Adding a new smoother algorithm, the Savitzky-Golay smoother to the smoother server plugin list. See the configuration guide Savitzky-Golay Smoother for more details.

Changes to Map yaml file path for map_server node in Launch

PR #3174 adds a way to set the path to map yaml file for the map_server node either from the yaml file or using the launch configuration parameter map giving priority to the launch configuration parameter. yaml_filename is no longer strictly required to be present in nav2_params.yaml.

SmootherSelector BT Node

PR #3283 adds a BT node to set the smoother based on a topic or a default. See the configuration guide SimpleSmoother for more details.