Robust Controller Design for Flapping-Wing Micro-aerial Vehicles Based on a T–S Fuzzy Approach

Abstract

This paper investigates a robust Takagi–Sugeno (T–S) fuzzy controller for flapping-wing micro aerial vehicles (FWMAVs) subject to actuator saturation and external disturbances. To this end, we first construct a state-scheduled T–S fuzzy model to represent the longitudinal dynamics of FWMAVs, explicitly accounting for state-dependent nonlinearities. Based on this model, we propose a two-loop control architecture: an inner-loop T–S fuzzy controller that regulates the vertical position and pitch angle, and an outer-loop PD controller that achieves full position-tracking by generating a pitch reference from the desired longitudinal position. Then, we formulate the T–S fuzzy stabilization conditions as linear matrix inequalities (LMIs) that guarantee closed-loop stability. Specifically, by exploiting the mismatch between the current and subsequent fuzzy basis functions (FBFs), we introduce a relaxation method that incorporates additional slack variables into the stabilization conditions, thereby reducing conservatism. Finally, numerical comparisons and simulations for FWMAVs are presented to verify the reduced conservatism and effectiveness of the proposed method.