Real Time Burst Signal Removal Using Multicolor Pyrometry Based Filter for Improved Jet Engine Control

Abstract

Online lineofsight (LOS) pyrometer is used on certain jet engines for diagnosis and control functions such as hotblade detection, hightemperature limiting, and conditionbased monitoring. Hot particulate bursts generated from jet engine combustor at certain running conditions lead to intermittent highvoltage signal outputs from the LOS pyrometer which is ultimately used by the onboard digital engine controller (DEC). To study the nature of hot particulates and enable LOS pyrometer functioning under burst conditions, a multicolor pyrometry (MCP) system was developed under DARPA funded program and tested on an aircraft jet engine. Soot particles generated as byproduct of combustion under certain conditions was identified as the root cause for the signal burst in a previous study. The apparent emissivity was then used to remove burst signals. In current study, the physics based filter with MCP algorithm using apparent emissivity was further extended to realtime engine control by removing burst signals at real time (1 MHz) and at engine DEC data rate. Simulink models are used to simulate the performances of the filter designs under engine normal and burst conditions. The results are compared with current LOS pyrometer results and show great advantage. The proposed model enables new LOS pyrometer design for improved engine control over wide range of operating conditions.