Adaptive Closed-Loop Control Allocation-Based Fault Tolerant Flight Control for an Overactuated Aircraft

Binwen Lu,Zhiqiang Zheng,Jianjun Ma

doi:10.1109/access.2019.2956818

Abstract

This paper discusses the adaptive control allocation based fault tolerant flight control problem for an overactuated aircraft in the presence of unknown uncertainties and actuator faults. Inspired by the feedback of control moments, an innovative adaptive closed-loop control allocation scheme with an estimator for the uncertainties is designed to tackle the distinct non-monotonic and the coupled nonlinearity caused by actuator failures or faults. Furthermore, since actuator faults will cause difficulty in modeling the aircraft dynamics precisely, an adaptive super twisting sliding mode controller is developed to track the reference trajectory. The convergence of the adaptive closed-loop control allocation and the stability of the fault tolerant flight control system is analyzed. Simulation results indicate the effectiveness and performance of the developed controller.

Highlights

Over the last three decades, the problem of fault tolerant control (FTC) has been intensively studied with the growing demand for safety, reliability and maintainability in modern industrial systems [1], [2]
Since the retrieval fails for the desired virtual moments required by the upper basic control law, neglecting the nonlinearities of mapping function would cause degradation or instability of the flight control system.Some researches on this problem have been carried out via adopting nonlinear optimal programming technique [28] and intelligence evolution algorithm [29], [30], adaptive fault tolerant control allocation with considering of non-monotonic nonlinearity of control surfaces remains as a challenge for flight control system design of the overactuated aircraft [31], [32]
Theorem 1: Consider the adaptive closed-loop control allocation based on (45) and (60), which integrated with the super-twisting sliding mode controller (23) and (27), the proposed nonlinear FTC scheme guarantees the system (1) asymptotic stability in the presence of actuator malfunctions

Summary

INTRODUCTION

Over the last three decades, the problem of fault tolerant control (FTC) has been intensively studied with the growing demand for safety, reliability and maintainability in modern industrial systems [1], [2]. Since the retrieval fails for the desired virtual moments required by the upper basic control law, neglecting the nonlinearities of mapping function would cause degradation or instability of the flight control system.Some researches on this problem have been carried out via adopting nonlinear optimal programming technique [28] and intelligence evolution algorithm [29], [30], adaptive fault tolerant control allocation with considering of non-monotonic nonlinearity of control surfaces remains as a challenge for flight control system design of the overactuated aircraft [31], [32]. Considering the adverse effects of FDI model on the rapidity and accuracy of fault-tolerance controller, a novel closed-loop control allocation based nonlinear sliding model adaptive fault-tolerant control scheme is proposed for a class of aircraft system with multiple actuators. The structure diagram of proposed control scheme is show in figure 1

SUPER-TWISTING SLIDING MODE CONTROL DESIGN

DESIGN OF ADAPTIVE CLOSED-LOOP CONTROL ALLOCATION

MAIN RESULT

NUMERICAL SIMULATION

CONCLUSION