Initial nav2 changes for swerve

[ErikCald]

Made a few changes to improve nav2 for the better chassis.

Some notable things:

• fixed bug in cprt_costmap_plugins::GridmapLayer that was clamping our 200 lethal cost threshold to 100
• Replaced costmap footprint with a tiny robot_radius since the planner and controller should be driving like an infinitely small point because its handled by elevation mapping inflation filter.
• Set global costmap robot_radius to 0.2 meters more than local costmap so the planner goes farther away than the collision checking to avoid getting stuck
• Increased update frequency of costmaps so its more update to date when its used
• Rotation shim controller
• Tighter turning radius
• New recovery in bt: backup 0.3 meters then spin 180 degrees

This commit is easier to read the changes since I moved the order of some configs in nav2.yaml first: c02fbd2

[Copilot]

Pull request overview

This pull request implements navigation stack improvements for a swerve drive chassis upgrade, transitioning from a skid-steer platform to a 4-wheel independent swerve drive system. The changes focus on optimizing Nav2 configuration for the new chassis capabilities, fixing critical bugs in custom costmap plugins, and implementing swerve-specific control strategies.

Changes:

• Fixed critical costmap plugin bug that was clamping lethal cost threshold to 100 instead of 255, preventing proper gradient representation
• Replaced footprint-based collision checking with point robot configuration, leveraging upstream elevation mapping inflation
• Implemented rotation shim controller to enable point-turn-before-drive behavior for swerve chassis
• Updated behavior tree with forward-only recovery sequence (backup 0.3m, then spin 180°)
• Fixed "trasversability" → "traversability" spelling errors across multiple configuration files
• Increased costmap update frequencies from 1-2 Hz to 10 Hz for more responsive collision checking
• Reduced minimum turning radius from 0.80m to 0.40m to leverage tighter swerve turning capability

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Nav/navigation/params/nav2.yaml	Major configuration overhaul: implemented point robot costmap strategy, rotation shim controller, tighter planner parameters, updated velocity limits for indoor testing
src/Nav/navigation/launch/nav2.launch.py	Added namespace parameter to all nav2 nodes and changed default behavior tree to swerve-specific version
src/Nav/navigation/config/elevation_mapping/postprocessing_traversability.yaml	Fixed typo in output_topic from "trasversability_map" to "traversability_map"
src/Nav/navigation/behavior_trees/bt_swerve_dynamic_replanning.xml	New behavior tree with swerve-optimized recovery actions (backup + 180° spin sequence)
src/Nav/navigation/2026_changes.md	Comprehensive implementation guide documenting all 2026 navigation upgrades and architectural decisions
src/Nav/localization/config/rviz.views/basicNavMap.rviz	Updated topic reference from "/trasversability_map" to "/traversability_map"
src/Nav/elevation_mapping/rviz2/zed2i.rviz	Updated topic reference from "/trasversability_map" to "/traversability_map"
src/Nav/elevation_mapping/config/postprocessing/traversability_pipeline.yaml	Fixed typo in output_topic from "trasversability_map" to "traversability_map"
src/Nav/cprt_costmap_plugins/src/gridmap_layer.cpp	Critical fix: changed lethal_threshold clamp from 100 to 255, and fixed default layer_name spelling

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[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

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[Copilot]

The spelling correction from "trasversability" to "traversability" should also be applied to this rviz configuration file to maintain consistency across the codebase. The file src/Nav/navigation/rviz/traversibility_gridmap.rviz still contains the misspelling on lines 225 and 251.

[Copilot]

The documentation file describes setting desired_linear_vel: 1.0 for outdoor swerve agility (line 73 of 2026_changes.md), but the actual configuration sets it to 0.3 with a comment suggesting to increase it to 1.0 later. This discrepancy between the documentation's recommendation and the actual implementation could cause confusion. Consider updating the documentation to reflect that the current implementation uses conservative values for indoor testing, matching the actual configuration.

[Copilot]

The documentation file states "Global costmap runs at ~2Hz (sufficient for static terrain)" at line 184 of 2026_changes.md, but the actual configuration sets the global costmap update_frequency to 10.0 Hz. This inconsistency should be resolved. Based on the PR description mentioning "Increased update frequency of costmaps so its more update to date when its used", it appears the 10Hz value is intentional, so the documentation should be updated to reflect this change.