Continue, Abort, or Fall: Viability-Aware Policy Selection (VAPS) for Safe Humanoid Acrobatics
Preprint. VAPS is a safety layer for humanoid acrobatic robots that adds two backup policies—an abort policy that lands on its feet and a protective-fall policy—and selects among them plus the nominal tracking policy using short-horizon viability predictors. In simulation on a LimX Oli, it cut head-contact rate from 15.5% to 1.1% while keeping motion success nearly unchanged (79.2% vs 80.7%), and on the physical robot the full hierarchy achieved its intended objective in 15 of 18 side-flip trials. The work matters because it directly addresses the main cost of deploying dynamic humanoids: hardware damage from failed maneuvers.