A hybrid modeling approach combining machine learning and physical phenomenological methods to predict highly transient engine emissions
摘要
Climate change has made low-emission propulsion technologies an increasingly important focus of development. Battery-electric vehicles (BEVs), which operate locally emission-free and offer high overall efficiency, are one possible solution. However, they are limited by charging infrastructure and comparatively short ranges in the compact and midsize segments. Hybrid-electric vehicles (HEVs) can mitigate these disadvantages and can reduce fuel consumption and emissions relative to purely internal-combustion-engine vehicles. Full exploitation of these benefits requires dedicated operating strategies that can be developed efficiently in simulation environments—provided that precise models of the vehicle subsystems and the environment are available. This work investigates various approaches for modeling emissions during highly transient engine operation, with an emphasis on forecasting emissions under real-driving conditions. Purely physics-based models are computationally expensive and lose fidelity during transients, whereas purely data-driven models require large, carefully curated data sets. Accordingly, this paper proposes a novel single hybrid architecture that combines a physical-phenomenological combustion/emission model with a long short-term memory (LSTM) network through a lightweight gray-box fusion layer to predict NO