easynav_navmap_planner

Description

A* path planner operating over a NavMap triangular mesh.
The planner computes the minimum-cost path between the robot and the goal, taking into account both the geometric distance between triangles and the cost values stored in a selected NavMap layer (typically "inflated_obstacles").

Instead of simply avoiding non-free NavCels, the planner integrates their cost values (0–255) into the path evaluation. Cells marked as LETHAL_OBSTACLE or NO_INFORMATION are considered non-traversable, while inflated or inscribed cells are allowed but penalized proportionally to their cost.

This enables smoother and safer trajectories that still respect proximity constraints imposed by obstacle inflation.

Cost model

For two neighboring NavCels u and v, the edge cost is computed as:

[ \text{cost}(u,v) = d(u,v) \times \left(\text{cost_factor} + \text{inflation_penalty} \times \frac{c(v)}{253}\right) ]

where d(u,v) is the Euclidean distance between triangle centroids,
and c(v) is the cost value of cell v.
This formulation ensures that:

• cells near obstacles (high cost) are traversed only if geometrically necessary,
• lethal (254) and unknown (255) cells are not traversable.

Authors and Maintainers

• Authors: Intelligent Robotics Lab
• Maintainers: Francisco Martín Rico fmrico@gmail.com

Supported ROS 2 Distributions

| Distribution | Status | |—|—| | humble | | | jazzy | | | kilted | | | rolling | |

Plugin (pluginlib)

• Plugin Name: easynav_navmap_planner/AStarPlanner
• Type: easynav::navmap::AStarPlanner
• Base Class: easynav::PlannerMethodBase
• Library: easynav_navmap_planner
• Description: A* path planner over a NavMap triangular mesh using per-cell costs to compute the shortest safe path.

Parameters

All parameters are declared under the plugin namespace, i.e.
/<node_fqn>/easynav_navmap_planner/AStarPlanner/...

Note: The planner internally uses hardcoded values for layer_name (prefers "inflated_obstacles", fallback to "obstacles"), inflation_penalty (value used in cost calculation), cost_axial, and cost_diagonal. These are not runtime-configurable parameters.

Interfaces (Topics and Services)

Publications

| Direction | Topic | Type | Purpose | QoS | |—|—|—|—|—| | Publisher | <node_fqn>/<plugin>/path | nav_msgs/msg/Path | Publishes the computed A* path. | depth=10 |

This plugin does not create subscriptions or services directly; it retrieves all inputs from NavState.

NavState Keys

| Key | Type | Access | Description | |—|—|—|—| | goals | nav_msgs::msg::Goals | Read | Target pose(s) for path planning. | | robot_pose | nav_msgs::msg::Odometry | Read | Current robot pose (start position). | | map.navmap | ::navmap::NavMap | Read | NavMap containing geometry and cost layer. The planner reads costs from the layer specified in <plugin>.layer (default: "inflated_obstacles"). If that layer does not exist, it automatically falls back to "obstacles". | | path | nav_msgs::msg::Path | Write | Output path, computed as the lowest-cost route. |

TF Frames

The planner assumes frame consistency between NavMap, robot pose, and goals. No TF lookups are performed internally.

License

Apache-2.0

Changelog for package easynav_navmap_planner

0.2.1 (2026-02-27)

• 0.2.0
• GPLv3 -> Apache 2.0
• Documentation was corrected
• Add a base_footprint frame in TFInfo
• Remove C++20/C++23 features and update to new MethodBase interface
• TFInfo in RTTFBuffer
• Refactor to use TFInfo
• Referencing base class if ot void
• Optimize execution
• Cleanup unused headers
• Update sheets
• Contributors: Francisco Martín Rico, Francisco Miguel Moreno, Juan S. Cely G., Miguel

0.0.2 (2025-10-12)

• Reorganization initial
• Contributors: Francisco Martín Rico