Gust Estimation and Rejection with a Disturbance Observer for Proprioceptive Underwater Soft Morphing Wings

2026-02-04

AI Summary

This study addresses the significant degradation of stability and maneuverability experienced by underwater vehicles in shallow waters due to unsteady disturbances such as waves and currents. Inspired by marine organisms, this work proposes a soft, morphing wing that integrates proprioception with a disturbance observer. The wing achieves continuous shape adaptation through hydraulic actuation, while embedded curvature sensors provide real-time feedback on its deformation. By fusing this proprioceptive data with a disturbance observer, the system reconstructs angle-of-attack perturbations induced by incoming flow and actively suppresses lift fluctuations. This approach represents the first integration of proprioception and disturbance observation for soft underwater wings. Experimental results validate the accuracy of curvature-based angle-of-attack estimation and demonstrate enhanced disturbance rejection and stability of the vehicle in complex flow environments.

Technology Category

• Intelligent Robots: State Estimation
• Planning, Routing, and Scheduling: Activity and Plan Recognition
• Computer Vision: Low Level & Physics-based Vision

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

Unmanned underwater vehicles are increasingly employed for maintenance and surveying tasks at sea, but their operation in shallow waters is often hindered by hydrodynamic disturbances such as waves, currents, and turbulence. These unsteady flows can induce rapid changes in direction and speed, compromising vehicle stability and manoeuvrability. Marine organisms contend with such conditions by combining proprioceptive feedback with flexible fins and tails to reject disturbances. Inspired by this strategy, we propose soft morphing wings endowed with proprioceptive sensing to mitigate environmental perturbations. The wing's continuous deformation provides a natural means to infer dynamic disturbances: sudden changes in camber directly reflect variations in the oncoming flow. By interpreting this proprioceptive signal, a disturbance observer can reconstruct flow parameters in real time. To enable this, we develop and experimentally validate a dynamic model of a hydraulically actuated soft wing with controllable camber. We then show that curvature-based sensing allows accurate estimation of disturbances in the angle of attack. Finally, we demonstrate that a controller leveraging these proprioceptive estimates can reject disturbances in the lift response of the soft wing. By combining proprioceptive sensing with a disturbance observer, this technique mirrors biological strategies and provides a pathway for soft underwater vehicles to maintain stability in hazardous environments.

Problem

• hydrodynamic disturbances
• underwater vehicle stability
• proprioceptive sensing
• soft morphing wings
• disturbance rejection

Innovation

• proprioceptive sensing
• disturbance observer
• soft morphing wings
• hydrodynamic disturbance rejection
• curvature-based estimation