Real Time Hybrid Switching Control of Automotive Cold Start Hydrocarbon Emission

Abstract

Reduction of cold start hydrocarbon (HC) emissions requires a proper compromise between low engineout HC emission and fast lightoff of the three way catalytic converter (TWC). In this paper, a hybrid switching system is designed and optimized for reducing HC emissions of a midsized passenger car during the cold start phase of FTP75 (Federal Test Procedure). This hybrid system has the benefit of increasing TWC temperature during the early stages of the driving cycle by switching between different operational modes. The switching times are optimized to reduce the cumulative tailpipe HC of an experimentally validated automotive emission model. The designed hybrid system is tested in realtime on a real engine control unit (ECU) in a modelintheloop structure. The results indicate the new hybrid controller reduces the HC emissions over 6.5% compared to nonswitching cold start controller designs.