An adaptive recursive sliding mode attitude control for tiltrotor UAV in flight mode transition based on super-twisting extended state observer

TL;DR

This paper presents an adaptive recursive sliding mode control method combined with a super-twisting extended state observer for tiltrotor UAVs, improving attitude control during flight mode transitions by enhancing disturbance rejection.

Contribution

It introduces a novel STESO-ARSMC control scheme that integrates state estimation and adaptive control for tiltrotor UAVs, addressing nonlinearities and disturbances during transition modes.

Findings

Enhanced anti-disturbance performance demonstrated in simulations

Finite-time convergence of the control system achieved

Effective attitude control during flight mode transition

Abstract

With the characteristics of vertical take-off and landing and long endurance, tiltrotor has attracted considerable attention in recent decades for its potential applications in civil and scientific research. However, the problems of strong couplings, nonlinear characteristics and mismatched disturbances inevitably exist in the tiltrotor, which bring great challenges to the controller design in transition mode. In this paper, we combined a super-twisting extended state observer (STESO) with an adaptive recursive sliding mode control (ARSMC) together to design a tiltrotor aircraft attitude system controller in transition mode using STESO-ARSMC (SAC). Firstly, the six degrees of freedom (DOF) nonlinear mathematical model of tiltrotor is established. Secondly, the states and disturbances are estimated by the STES observer. Thirdly, ARSM controller is designed to achieve finite time convergence. The Lyapunov function is used to testify the convergence of the tiltrotor UAV system. The new aspect is that the assessments of the states are incorporated into the control rules to adjust for disruptions. When compared to prior techniques, the control system proposed in this work can considerably enhance anti-disturbance performance. Finally, simulation tests are used to demonstrate the efficacy of the suggested technique.