The influence of the applied window function and sampling frequency on the assessment accuracy of the turbine engine in flight control condition based on its ground tests

Karol Golak,Paweł Lindstedt,T Kałaczyński,M Żółtowski

doi:10.1051/matecconf/201818201024

Abstract

The article presents the basis of the method allowing to assess the state of control condition of a turbine jet engine during the plane flight when the input signal to the engine is unpredictable interference signal „z". Method is based only on signals acquired during engine ground test when the input signal is „w" delivered by technical support using the engine control lever (DSS). The control state of the engine both from the set value „w" and „z" is expressed by the quotient of its cross power spectral densities (in frequency domain). The way of transition from the frequency domain to the time domain was presented, it allows to obtain step responses of engine from „z" and „w", greatly facilitating the interpretation of the obtained results.. The analysis of the influence of choosing types of the window function and signals sampling frequency on the accuracy of the proposed model has been carried out.

Highlights

The aviation engine is used during the flight when, apart from the „w” signal set by pilot using the engine control lever (DSS), it is affected by unpredictable interference signal „z” delivered from the environment
To derive a model describing the assessment of the control quality of a jet engine with input „z” using only signals measured with input „w” during its standard ground tests, it is necessary to identify the transfer functions of individual elements of the automatic control system
According to the conducted simulation test, as a result of multiplication of HW(s) with 1/GR(s) could be obtained the HZ(s)

Summary

Introduction

The aviation engine is used during the flight when, apart from the „w” signal set by pilot using the engine control lever (DSS), it is affected by unpredictable interference signal „z” delivered from the environment. Engine is adjusted on the basis of signals recorded during its ground tests, when the input signal is only the signal „w” from the DSS, and the signal „z” has low power and are constant so it is often overlooked. This may lead to a situation where the aircraft properly adjusted during ground tests from the „w” signal may react inappropriately to the „z” interference signals occurring during the flight. It is known that improving the quality of the engine from „w” (on the ground) causes deterioration of the quality of the engine from „z” (in flight) [1, 2, 3, 5, 8]

Theoretical basis

Verification of the turbine engine control quality assessment method

Summary

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