Longitudinal Attitude Control Decoupling Algorithm Based on the Fuzzy Sliding Mode of a Coaxial-Rotor UAV

Abstract

A longitudinal attitude decoupling algorithm based on the fuzzy sliding mode control for a small coaxial rotor unmanned aerial vehicle (UAV) is presented in this paper. The attitude system of a small coaxial rotor UAV is characterized by nonlinearity, strong coupling and uncertainty, which causes difficulties pertaining to its flight control. According to its six-degree-of-freedom model and structural characteristics, the dynamic model was established, and a longitudinal attitude decoupling algorithm was proposed. A fuzzy sliding mode control was used to design the controller to adapt to the underactuated system. Compared with the uncoupled fuzzy sliding mode control, simulation results indicated that the proposed method could improve the stability of the system, presented with a better adapting ability, and could effectively suppress the modeling error and external interference of the coaxial rotor aircraft attitude system. The proposed method also has the advantages of high accuracy, good stability, and the ease of implementation.

Finite Time Convergence Incremental Nonlinear Dynamic Inversion-Based Attitude Control for Flying—Wing Aircraft with Actuator Faults

“…With model uncertainties and time delay in the inner loop, FINDI is used to design the controller. Therefore, the FINDI controller, based on Equations (13), (18), (21) and (31), is given as…”

“…In the control system, the state performance of the control system can be transferred into the constraint problem of tracking error performance. Traditionally, the nonlinear controller is designed to guarantee that the tracking error is converged to a residual set whose size depends on design parameters and some bounded though unknown terms [19][20][21]. However, no systematic procedure exits to accurately compute the required upper bounds, thus making the a priori selection of the design parameters to satisfy certain steady state behavior practically impossible.…”

Autonomous Control of Unmanned Aerial Vehicles

“…Therefore, a coaxial rotor aircraft has a compact structure, a small radial size, and a higher power efficiency. In their contribution, Li and co-authors [8] propose a decoupling algorithm to improve the reliability of the attitude control for the longitudinal motion stability of a coaxial rotor UAV. Based on a dynamic model that describes the vehicle's longitudinal motion, an under-actuated controller is designed using the fuzzy sliding-mode approach.…”

Fuzzy Adaptive Linear Active Disturbance Rejection Control for Quadrotor Load UAV Based on Kalman Filter

“…However, by integrating PID with fuzzy adaptive control, the resulting fuzzy-PID demonstrates rapid tracking capabilities with enhanced robustness. In the reference [25], it has crafted a fuzzy sliding mode controller tailored for longitudinal attitude decoupling, showcasing commendable adaptability. While the fuzzy controller excels in boosting system robustness and reaction times, its disturbance immunity could benefit from further refinement.…”