Title: Real-time emission test and evaluation method of heavy-duty diesel vehicle SCR system based on dynamic time warping

Authors: Xuejian Ma; Tao Qiu; Yan Lei; Zexun Chen

Addresses: Faculty of Environment and Life, Beijing University of Technology, Beijing 100000, China ' Faculty of Environment and Life, Beijing University of Technology, Beijing 100000, China ' Faculty of Environment and Life, Beijing University of Technology, Beijing 100000, China ' Faculty of Environment and Life, Beijing University of Technology, Beijing 100000, China

Abstract: Selective catalytic reduction (SCR) technology is the most important technique to solve the high NO_x emission of diesel vehicles. In-use heavy-duty diesel vehicles must undergo emission spot checks at inspection stations to avoid exceeding the NO_x emission limits due to abnormal operation of the SCR system. A method that can quickly carry out in-situ emission tests on heavy-duty diesel vehicles on the road to evaluate SCR operation status is of great significance. In this paper, a method based on dynamic time warping (DTW ) is proposed to quickly judge the SCR operation status when the vehicle is stationary. The variation of similarity between SCR inlet NO_x and SCR outlet O₂, the variation of similarity between SCR outlet O₂ and SCR outlet NO_x, and the effect of SCR working efficiency on SCR outlet O₂ were analysed through experiments, and the proposed method was validated.

Keywords: selective catalytic reduction technology (SCR); DTW; Dynamic time warping; SCR outlet NO_x; SCR outlet O₂; diesel vehicle.

DOI: 10.1504/IJHVS.2025.147048

International Journal of Heavy Vehicle Systems, 2025 Vol.32 No.3, pp.304 - 326

Received: 11 Oct 2023
Accepted: 11 Jan 2024
Published online: 10 Jul 2025 *

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