Active fault-diagnosis method using adaptive allocator and fault-tolerant adaptive control system design

Natsuki Kawaguchi,Nozomu Araki,Takao Sato,Toshihiko Asami,Masaharu Kuroda

doi:10.1186/s40648-020-00175-0

Abstract

A new approach to the active fault diagnosis (AFD) for input redundant plants is presented in this paper. A test signal which helps the diagnosis is injected to the plant in addition to nominal control input in the AFD typically. One feature of the proposed AFD is adaptive allocation of the test signal. The adaptive allocator which distributes the test signal and injects it to the redundant actuators is introduced in this paper. A fault-diagnosis (FD) system that estimates fault location and its magnitude from adaptive parameter of the adaptive allocator is constructed with a simple neural network (NN) model. Furthermore, a A fault-tolerant adaptive control system which includes the adaptive test signal allocator is designed based on the model reference adaptive control (MRAC) technique. The adaptive laws of the adaptive allocator and controller are derived by using a suitable Lyapunov function. By performing experiments using a two-input redundant plant, we show the effectiveness and applicability of the proposed AFD and MRAC system.

Highlights

Many machine-based systems consist of actuators, sensors, computers, and mechanical elements
In “Fault-tolerant adaptive control design with adaptive allocator” section, we show the derivation of the adaptive law for the controller and allocator using a suitable Lyapunov function [29]
Fault‐tolerant adaptive control design with adaptive allocator we describe the design of an fault-tolerant adaptive control system with an adaptive allocator for testsignal injection and actuator faults [29]

Summary

Introduction

Many machine-based systems consist of actuators, sensors, computers, and mechanical elements. To improve the actuation and/or fault tolerance performance, input-redundant systems have been developed which have one or more additional actuators [2,3,4]. Based on the fault tolerance of redundant plants, it is possible to eliminate the faulty influence on the system. A self-repairing control system converts faulty actuators into healthy ones, and fault accommodation is performed with the remaining healthy actuators in adaptive control systems [5,6,7,8,9]. A number of studies that address the fault-diagnosis (FD) problem have been developed [11,12,13,14,15,16].

Methods

Findings

Conclusion