低忠実度シミュレータで実現するロボット魚のゼロショットsim-to-real制御
All You Need Is Low Fidelity: Zero-Shot Sim-to-Real of Learned Robotic Fish Control
低忠実度の流体モデルと帯域制限された軌道生成器を用いて、ソフトロボット魚の閉ループ制御をシミュレータから実機へチューニングなしで転移させた。
著者: Liam Maloney, Simon Ramchandani, Mike Y. Michelis, Ronan Hinchet, Robert K. Katzschmann
分類: cs.RO
原文アブストラクト
Complex tasks for underwater robots remain limited by the capabilities of their controllers. Learning a better one for a soft, underactuated robotic fish trades simulator cost against fidelity. We show that an intentionally low-fidelity simulator is enough: a stateless, quasi-steady fluid model with no wake and no added-mass history suffices to learn a \emph{general}, closed-loop controller that transfers to hardware without tuning. Our platform is a soft, single-motor, tendon-driven fish whose policy observes only what the hardware can measure. A staged pipeline grounds the simulator in two independent identifications, fixing the tail dynamics and a stateless fluid model; the policy then acts through a band-limited rhythmic trajectory generator rather than commanding the tail directly. Deployed unchanged in an outdoor pool, a single policy performs closed-loop target reaching, disturbance rejection, and out-of-distribution target acquisition and tracking. The transfer rests on the constraint rather than the fidelity: the generator cannot leave the band over which the fluid was identified. This raises the question of how much of the physics can reside in the controller rather than in the simulator.