Week 12 — Phase 3 Complete, 9 Days Early

Rebuilt Phase 2 from scratch in one day, achieved formation control, then completed Phase 3 ahead of schedule.

Week 12 — Phase 3 Complete, 9 Days Early

Rebuilt Phase 2 from scratch, achieved formation control in a single session, then blew through Phase 3 — finishing 9 days ahead of schedule.

Milestones

  • Fresh start on Phase 2 — and finished in one day. Archived the old codebase, rebuilt from the Isaac Lab quadcopter reference, and achieved working formation control all in a single session.
  • Phase 2A (hover): Solved with DirectRLEnv + PPO shared policy (CTDE). 4 runs to reach ep_len 499/500.
  • Phase 2B (formation): 8 runs with progressive fixes — from formation reward at zero (p2b-1) to stable triangle formation with zero crashes (p2b-8).
  • Phase 3: Complete. MINCO trajectory optimization, CBF safety shields, and SwarmRaft consensus logic all integrated — 9 days ahead of the original Apr 7 target.

Key Bugs Squashed

  • SKRL bypasses gym wrappers — moved formation logic into the env
  • env_origins subtraction missing from neighbor observations
  • Episode timeout stagger caused drone “despawn” — synced within groups
  • Corrected circumradius formula for formation offsets
  • Group-aware goal sampling with shared centroid.

Next Steps

  • Begin Phase 4: Stress Testing — agent loss simulations, obstacle benchmarks, and scale testing

Challenges

  • The Phase 2 rebuild was a tough call but paid off immediately. Starting clean from the reference implementation eliminated accumulated technical debt from weeks of incremental patches.