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The conventional aftertreatment systems to meet the stringent ULEV-II emission regulation are usually composed of warm-up catalytic converter (WCC) and underfloor catalytic converter (UCC). However, those systems bring high cost, high back pressure, the limit of engine room for package design, and other side effects.[4] The new optimized system needs to solve these problems and to meet ULEV-II emission regulation efficiently. There are many technologies and design parameters in exhaust catalytic converter systems; exhaust manifold structure[9], exhaust gas flow distribution, location of catalytic converter, PM coating technologies[1], substrate characteristics, and volume of catalysts. It is a key factor to make a optimized robust system with those parameters and technologies described. The new optimized exhaust and Integrated Close-coupled Catalytic Converter (ICCC) system can meet ULEV-II regulation and can solve those problems of conventional system by a robust design.

A new fuel economy optimization method for parallel hybrid electric vehicles with continuously variable transmission( CVT) is proposed in this paper. The method maximizes overall system efficiency while meeting desired performances. Firstly, effective specific fuel consumption (ESFC) is defined as effectively consumed fuel per output power-hour from a hybrid propulsion system, in which battery output power is transformed into an equivalent amount of fuel. Hence, hybrid optimal operation line(HOOL) is derived based on ESFC as optimal operation line(OOL) is found based on specific fuel consumption( SFC) in a conventional internal combustion engine(ICE) vehicle with CVT. From HOOL, optimal combinations of control variables, CVT gear ratio, motor torque and engine throttle, are obtained versus vehicle velocity, battery state of charge and required power. A simulation study with the proposed optimization method is performed to prove its validity.