Title: Control-oriented observer for cylinder pressure estimation of SI engine using frequency response function

Authors: Syed Abbas Ali; Samir Saraswati

Addresses: Department of Mechanical Engineering, SECAB IET, Vijaypur, 586109, India ' Mechanical Engineering Department, MNNIT, Allahabad, 211004, India

Abstract: This paper presents a closed-loop control-oriented observer (COB) for in-cylinder pressure estimation, which utilises a one zone combustion model in the feed-forward loop and frequency response function (FRF) model in the feedback loop. The model uses the phase difference in firing frequency of crankshaft speed as a measure to update COB parameters. The update rate of control parameters in the COB is one engine cycle. The COB is found observable at the top dead centre (TDC). The applicability of the proposed model is illustrated by simulation and experimental results. Further, a comparative study using closed-loop COB, FRF, and sliding mode observer (SMO) methods, is also presented.

Keywords: frequency response functions; FRFs; control-oriented observer; COB; cylinder pressure.

DOI: 10.1504/IJMIC.2021.123427

International Journal of Modelling, Identification and Control, 2021 Vol.39 No.2, pp.138 - 149

Received: 23 Oct 2020
Accepted: 09 May 2021

Published online: 20 Jun 2022 *

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