DESIGN AND RESEARCH ON SCR SYSTEM CONTROL MODEL BASED ON SIMULINK

Abstract

As a core aftertreatment technology for diesel engine exhaust, selective catalytic reduction (SCR) systems have attracted extensive research attention from domestic automotive manufacturers. Based on a self-developed urea dosing pump, this paper establishes the operating workflow of the SCR system and selects the Freescale MC9S12XS128 microcontroller as the core hardware of the aftertreatment control unit (ACU). A SCR system control model is constructed via MATLAB/Simulink, with executable C codes automatically generated from the established model to shorten development cycles and reduce overall system development costs. A four-cylinder in-line diesel engine is configured for the bench test, and multiple ESC and WHTC cycle experiments are carried out on the AVL GEM30 automated exhaust emission test bench. Experimental results verify that the proposed development framework combining Simulink-based modeling, modular control strategies and automatic C-code generation is feasible, efficient and reliable. The developed SCR system delivers superior control performance and remarkable NOₓ reduction capability in practical engineering applications.