SSS-VIO: Strawberry Squid Asymmetrical Eyes Bio-Inspired Stereo Visual Inertial Odometry

Visual-inertial odometry (VIO) serves as a dominant framework for real-time motion state estimation in micro aerial vehicles (MAVs). However, existing VIO techniques remain highly susceptible to high dynamic range (HDR) illumination conditions. Bio-inspired by the lateralized visual system of the Strawberry Squid, we propose a SSS-VIO technique that integrates a functionally asymmetric-eye design and perceptual attention mechanisms to overcome HDR-induced limitations. The proposed method is applicable both to the design of asymmetric stereo platforms and to cost-effective retrofitting of commercial stereo cameras. Experimental evaluations on an OAK-4P-New camera demonstrate a 40% increase in usable dynamic range with a single neutral density filter. Furthermore, SSS-VIO also outperforms multiple state-of-the-art VIO methods in MAV flight tests, reducing Absolute Trajectory Error by at least 46.1% and consistently improving Relative Pose Error across different trajectory segments. To the best of our knowledge, this is the first bio-inspired asymmetric-eye solution for enhancing the VIO dynamic range, which might unlock new potentials for MAV indoor-outdoor localization and applications.