Summit playground: parking garage world

[fmrico]

Fixes #5

A third Summit XL world: a parking garage with three floors over the same footprint, linked by ramps. It is the first playground where the robot plans and drives between floors.

ros2 launch easynav_playground_summit easynav_parking_garage.launch.yaml

Contents

• World and models. worlds/parking_garage.world (plus the .sdf and _mapping variants), models/parking_garage, models/parking_garage_ground_plane and the *_cube models, from parking-garage-world.
  • Its license file is GPL-3.0, now in models/parking_garage/LICENSE and declared in package.xml.
  • The garage model is based on a model by michaelwjl on free3d.com, credited in the README. Please check the license of that original model before merging.
• Maps. They come from simulated 3D lidar scans of the collision mesh (a VLP-16 0.8 m above the ground every 2 m on floors 0–2), so faces hidden inside the model never enter them.
  • maps/parking_garage.pcd: 8.4 MB, one point per 0.1 m voxel (centroid), map frame.
  • maps/parking_garage.navmap: from_points at 0.4 m. Floors 0–2 and the ramps are one surface that overlaps itself in XY; the roof is a separate surface, unreachable in the model.
  • maps/parking_garage_bonxai.pcd: one point per occupied 0.3 m voxel.
• Launch and parameters. easynav_parking_garage.launch.yaml and params/parking_garage.amcl.params.yaml. The parameters are the warehouse's (indoor RPP, NavMap AMCL with Bonxai, A* over the NavMap): obstacles only within 3 m and below 1.2 m, so the ceiling of each floor is not an obstacle.
• READMEs. Both document the world, how its maps were built and the launch file.

Depends on

• Rewrite from_points as a multi-level grid mesher NavMap#31: the multi-level mesher. The map was built with it, but the file format is unchanged.
• Add NavMap::distance_field NavMap#33 and NavMap InflationFilter: inflate from 3D distances to the real border easynav_plugins#116: with the previous inflation, border cells were lethal, so the 2.9 m ramps came out blocked for the 0.7 m inscribed radius and the robot did not leave floor 0.

Validation

Headless simulation, goal (5, 0) on another floor:

Goal	Result	Time	Path driven	Climb
Floor 1 (z 2.35)	FINISHED	62 s	45 m	2.35 m
Floor 2 (z 4.70)	FINISHED	129 s	102 m	4.70 m

The robot goes up the north ramp 0→1, crosses floor 1 and goes up the ramp 1→2. EasyNav's z estimate follows the real one all the way.

Known limits.

• With the 0.7 m inscribed radius the ramps leave about 0.9 m of clearance at 0.4 m cells, and less at other resolutions. The real Summit is about 0.62 m wide.
• The final goal error (~0.6 m) comes from the localization (AMCL against Bonxai).