KINLOCK: Bimanual VLA Flight Envelope Protection

Vision-Language-Action (VLA) models propose actions at 10–30 Hz, while physical robot servos execute at 1,000 Hz. In bimanual tasks—such as two robot arms carrying an object together—this frequency gap causes kinematic drift between the end-effectors. Documented in Hugging Face LeRobot Issue #3154, this drift generates over 2,000 N of internal tensile and compressive force, stripping servo gears and destroying physical hardware. KINLOCK provides deterministic, sub-millisecond Flight Envelope Protection (FEP) for dual-arm robotic systems. Positioned directly between any high-level VLA model and low-level servo controllers, KINLOCK projects unconstrained velocity proposals onto the null-space of closed-chain kinematic constraints using Moore-Penrose pseudo-inversion and Baumgarte drift stabilization (α = 12.0 s⁻¹). Benchmarked against dual SO-101 6-DOF arms on a 150-frame table-setting dataset, KINLOCK reduces peak internal strain from 2,033.99 N down to 0.02 N (100% attenuation) within a 72.5 μs callback dispatch, strictly preserving the 348.24 mm grasp invariant without interrupting ongoing task execution. Additionally, KINLOCK integrates Speechmatics Realtime WebSocket API for acoustic emergency reflexes. When an operator utters "STOP" or "HALT", KINLOCK parses the phoneme stream and triggers an exponential admittance deceleration curve: bringing arm velocities to a complete halt in under 50 ms while sustaining 100% gripper clamp torque so carried objects never drop.