Fault simulation of the sensors in gasoline engine control system

Abstract

The control system of the gasoline engine requires the information about its current condition. These are the information which have to be transferred into electric signals. In the mechatronic control systems of the combustion engines, non-electric quantities are changed into electric signals by way of the converters called sensors. Like all technical devices, sensors can be damaged. They are also the subject of the aging process based on the change of the converting characteristics. If the breakdown is based on the change of the sensor characteristics, it will indicate the value of the measured quantity with a certain error. The system of on-board diagnostics is supposed to detect the faults including wrong indications of the sensors. Unfortunately, not all the faults are detected and some of them are masked by the adaptive function of the control system. The aim of this project is to prove that there are many possibilities of the detection of wrong indication of the sensor. It is possible even in case when its signal is within the voltage limits defined for it. It requires the analysis of several signals simultaneously. Comparing a current value of the signal with a typical one for a particular point of work will allow us to detect possible indication error of the sensor. Typical values have to be in the shape of database as a function of other signals (e.g. in the shape of so-called maps). This project presents the studies based on the simulation of faults of chosen sensors. Based on the analysis of several signals simultaneously, it is possible to deduce the accuracy of the indication of a particular sensor.