Finite time fault-tolerant attitude control for rigid-flexible coupling satellites based on Legendre neural network

Abstract

This paper investigates the finite time fault-tolerant attitude control for rigid-flexible coupling satellites in large angle rapid maneuver when some of the actuators are in the fault condition. Based on the first-order approximate method, a more accurate dynamic model for rigid-flexible coupling satellites is set up. Then, Legendre polynomial-based neural network is introduced to estimate the lump perturbation including the estimation error of the fault control torque, high-order flexible coupling terms, external disturbances, and model uncertainties. With the estimation value as the compensation effort, a finite time fault-tolerant attitude controller is designed based on the nonsingular fast terminal sliding mode. And in order to guarantee that the output of the Legendre polynomial-based neural network stays inside the bound of the lump perturbation, a switch mechanism is introduced to generate a switching between the proposed fault-tolerant attitude controller and a robust controller. The proposed fault-tolerant attitude controller is shown to have the finite time stability, with fast convergence rate, high accuracy, disturbance rejection, chattering attenuation, flexible vibration damping through theoretical analysis and simulations, meanwhile the better representation capability of the Legendre polynomial-based neural network, whose basic functions are implemented using only the desired attitude, makes the controller design simple and efficient.

Finite-Time Control Algorithm Based on Modal State Observer for Flexible Satellite Attitude Tracking

“…However, the convergence rate of standard state observer based on linear feedback is exponential. In order to get the finite time state observer, integrate (1) on both sides dt + + = − ∫  η η K η δω (13) Define ζ and y as follows…”

Advanced fault detection and diagnosis in spacecraft attitude control systems: Current state and challenges

“…Additionally, some studies have involved fault-tolerant attitude control in which reaction wheels are used to control satellites for different purposes while considering various constraints like saturation, redundancy, flexibility, angular velocity knowledge, or fault information. 20,[186][187][188][189][190][191][192] Furthermore, it was shown that different selections of attitude sensors could affect the necessity of an active FTC. For example, Wang et al 193 proposed an adaptive fault-tolerant attitude control system for the rigid body satellite affected by actuator faults, space environmental disturbances, and several system uncertainties.…”

Fault-tolerant control of flexible satellite with magnetic actuation and reaction wheel

“…Similarly, there are some studies on the faulttolerant attitude control of satellites using reaction wheels for different goals and considering various constraints like saturation, redundancy, flexibility, angular velocities knowledge, or fault information. [7][8][9][10][11][12][13][14] One of the other challenges in modern missions, like missions with high power payloads, is the demand for large appendages, like solar panels. [15][16][17] Also, the size constraints of launching and injecting the spacecraft into orbit leave the deployable solar panels a considerable choice.…”

“…20 The core model of a satellite with flexible panels in the mentioned articles is based on the represented model of Monaco and Stornelli 19 and used without validation. On the other hand, most of the other studies just assume a fixed and bounded error in the moment of inertia and proposed an FTC [7][8][9][21][22][23][24][25][26][27] with different goals and control methods.…”