Sim-to-Real Transfer for Underwater Wireless Optical Communication Alignment Policy between AUVs

Abstract

The underwater wireless optical communication (UWOC) technology provides a potential high data rate solution for information sharing between multiple autonomous underwater vehicles (AUVs). In order to deploy the UWOC system on mobile platforms, we propose to solve the optical beam alignment problem by maintaining the relative position and orientation of two AUVs. A reinforcement learning based alignment policy is transferred to the real world since it outperforms other baseline approaches and shows good performance in the simulation environment. We randomize the simulator and introduce the disturbances, aiming to cover the real distribution of the underwater environment. Soft actor-critic (SAC) algorithm, reward shaping based curriculum learning, and specifications of the vehicles are utilized to achieve the successful transfer. In the Hiratsuka sea experiments, the alignment policy was deployed on the AUV Tri-TON and successfully aligned with autonomous surface vehicle BUTTORI. It demonstrates a solution for combining the UWOC technology and AUVs team in the ocean investigation.

Pointing Error Control of Underwater Wireless Optical Communication on Mobile Platform

“…The hovering AUV Tri-TON was used as the host platform, while the ASV BUTTORI served as the target platform for underwater optical communication. To shorten the pointing error d ∆ in the experiment, an motion planning method was deployed on the AUV Tri-TON, which was validated in simulations in previous studies [16] [17]. No global navigation satellite system service or radio communications were used since it is not available underwater.…”