Skip to content

Local Packages

The local layer closes the robot's short-range sense-plan-act loop: a fast local world model built from live sensor data, a reactive local planner that avoids obstacles the global map is too slow or too coarse to capture, and the controllers that turn planned trajectories into commands for the interface. The loop is coupled through the trajectory controller's look-ahead point — the local planner plans forward from where the controller will soon be, and streams trajectory segments back to it.

Sub-layers

  • World Model — disparity-based C-space obstacle representation for fast collision queries
  • Planning — the DROAN local planner: turns the global plan into short, collision-free trajectory segments
  • Controls — trajectory controller (tracking/look-ahead point management) and PID controller (attitude/thrust commands)

Launch

Local modules ship their own canonical launch files and are composed flat by the selected stack's entry launch file (stacks/<name>/launch/*.launch.xml) — the trunk stacks include takeoff_landing_planner, the trajectory controller, droan_gl, and the PID controller directly; see stacks/full_default/launch/stack.launch.xml for the composed wiring.

Key Interchanges

  • global_plan (§4) — the coarse path handed down from the global layer; the local planner's main input
  • trajectory group (§5) — the trajectory controller's onboard-only contract: trajectory_segment_to_add, trajectory_override, tracking_point, look_ahead
  • control_setpoint (§6) — the PID controller's command into the interface layer

See Also