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Indexed by:期刊论文

Date of Publication:2016-01-25

Journal:APPLIED THERMAL ENGINEERING

Included Journals:SCIE、EI

Volume:93

Page Number:251-259

ISSN No.:1359-4311

Key Words:Combustion engine; Residual gas fraction; Performance; Optimal control; Stochastic logical dynamics; Variable valve timing

Abstract:In four stroke internal combustion engines, residual gas from the previous cycle is an important factor influencing the combustion quality of the current cycle, and the residual gas fraction (RGF) is a popular index to monitor the influence of residual gas. This paper investigates the cycle-to-cycle transient behavior of the RGF in the view of systems theory and proposes a multi-valued logic-based control strategy for attenuation of RGF fluctuation. First, an in-cylinder pressure sensor-based method for measuring the RGF is provided by following the physics of the in-cylinder transient state of four-stroke internal combustion engines. Then, the stochastic property of the RGF is examined based on statistical data obtained by conducting experiments on a full-scale gasoline engine test bench. Based on the observation of the examination, a stochastic logical transient model is proposed to represent the cycle-to-cycle transient behavior of the RGF, and with the model an optimal feedback control law, which targets on rejection of the RGF fluctuation, is derived in the framework of stochastic logical system theory. Finally, experimental results are demonstrated to show the effectiveness of the proposed model and the control strategy. (C) 2015 Elsevier Ltd. All rights reserved.