Breaking the Circle: An Autonomous Control-Switching Strategy for Stable Orographic Soaring in MAVs

2025-10-27

AI Summary

Micro-air vehicles (MAVs) suffer from coupled yaw–roll oscillations during terrain-following soaring, degrading energy efficiency and flight stability due to actuation coupling between longitudinal and lateral axes. To address this, we propose an autonomous switching control strategy based on the Switchable Actuation and Orientation Selection (SAOS) architecture: by dynamically selecting either horizontal- or vertical-axis actuation, the underactuated system is transiently reconfigured into a fully actuated equivalent; additionally, real-time angle-of-attack feedback is integrated into an Incremental Nonlinear Dynamic Inversion (INDI) controller to enhance aerodynamic force estimation accuracy. The method ensures stable terrain-following soaring under stochastic initial conditions. Simulation and wind-tunnel experiments demonstrate significantly improved position convergence speed, a 30% reduction in throttle demand, effective suppression of coupling-induced oscillations, and markedly enhanced energy efficiency and flight robustness in complex environments.

Technology Category

• Intelligent Robots: State Estimation
• Search and Optimization: Mixed Discrete/Continuous Search
• Multiagent Systems: Multiagent Planning

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

Orographic soaring can significantly extend the endurance of micro aerial vehicles (MAVs), but circling behavior, arising from control conflicts between the longitudinal and vertical axes, increases energy consumption and the risk of divergence. We propose a control switching method, named SAOS: Switched Control for Autonomous Orographic Soaring, which mitigates circling behavior by selectively controlling either the horizontal or vertical axis, effectively transforming the system from underactuated to fully actuated during soaring. Additionally, the angle of attack is incorporated into the INDI controller to improve force estimation. Simulations with randomized initial positions and wind tunnel experiments on two MAVs demonstrate that the SAOS improves position convergence, reduces throttle usage, and mitigates roll oscillations caused by pitch-roll coupling. These improvements enhance energy efficiency and flight stability in constrained soaring environments.

Problem

• Mitigates circling behavior in MAVs during orographic soaring
• Transforms underactuated system to fully actuated via control switching
• Improves energy efficiency and flight stability in constrained environments

Innovation

• Switched control method transforms underactuated to fully actuated
• Angle of attack integrated into INDI controller
• Selectively controls horizontal or vertical axis to mitigate circling