biflow_chess_60hz_parity

BiFlow (one-step normalizing-flow) policy for SO-101 chess. 60 Hz control timeline, 30 Hz held cameras. fkloss-recipe parity: z-weighted loss (pickup 3 / dropoff 3), FK-space loss (lambda 1, 5mm/5deg, parity 4.71e-03), phaseweight sampling W=2.5 (38.2% -> 59.3% precision share).

• Data: AnonymousMouse404/chess (357 eps, excl. 37+294), board(highlighted)+wrist+state, 128px
• 50k steps (10k forward pretrain + 40k reverse), batch 32, seed 1000, lr 1e-4 AdamW cosine
• Load: pip install -e the BiFlow_policy_MUTD_SO101_pick_place folder, import lerobot_policy_so101_biflow, then So101BiflowPolicy.from_pretrained(...). See deployment_contract.json.