Optimal Detector Design for On-line Testing of Linear Analog Systems

Emmanuel Simeu

doi:10.1155/2000/92954

Abstract

The design of integrated fault detector for on-line testing of linear analog systems is discussed in this paper. The method consists in a concurrent processing of available the node voltage signals to provide a residual on-line, that carries information about the faults. Contrary to the few previous works dealing with the particular case of state variable analog systems, the method proposed here is useable without limitation for a larger class of linear analog systems, even when the state variables are not available as measurable voltages. For this purpose, an algorithm providing an extended state space model for any linear analog system from its netlist description is developed and implemented.

Highlights

A novel fault detection methodology based on the use of analytical rather than physical redundancy has emerged and is increasingly discussed
The method described in the previous sections has been applied to different type of analog circuits including biquadratic filter, high pass filter, Pierce oscillator and the low pass filter example of Figure 2
The first part of this paper deals with the generation of an extended symbolic model for linear analog circuits from its netlist description. This extended model required for efficient on-line fault detection comprises state space matrices for the nominal model, an unknown noise input model and a fault model

Summary

Introduction

A novel fault detection methodology based on the use of analytical rather than physical redundancy has emerged and is increasingly discussed. For this purpose, the inherent redundancies contained in the static and dynamic relationships among the system input and measured signals are exploited. The basic principle of concurrent testing techniques consists in exploiting the mathematical knowledge available on the monitored system to generate a fault indicating signal (called residual). When the mathematical model is an accurate representation of the nominal system behavior, the residual characterizes the system operating mode: close to zero in normal operation, different from zero if there is a mismatch. The goal is to detect the faults of interest and their causes early enough so that a failing of the

Methods

Results

Conclusion