Abstract
Research and/or Engineering Questions/Objective
China’s Phase IV Corporate Average Fuel Consumption(CAFC) Standards has been issued, which requires the fleet-wide average fuel consumption rate(FCR) to decrease from 6.9L/100km to 5L/100km by 2020. In order to comply with the standards, one original equipment manufacturer(OEM) must select several sets of fuel-efficient technologies strategically from its arsenal to apply to the assortment at the best cost. This paper aims to explore the fuel-efficient technology roadmap for satisfying the phase-in standards from 2016 to 2020 though a case study.
Methodology
The technology combination problem is defined as selecting the technologies to be implemented on an OEM’s vehicle product assortment that can optimize the OEM’s targets subject to the constraints of FCR standards, which has proven NP-hard. A technology combination model is established by considering the cost, fuel consumption reduction effect and physical weight of 74 potential fuel-efficient technologies as well as the schemes and provisions of the standards. The cost is estimated by employing the methods of learning curves. The strategical decision making process of the OEM is considered in a multi-period time horizon. An intermediate volume OEM, whose assortment consists of 26 vehicle models sold domestically in China, is selected as a case. The overall combinational optimization problem is solved by an elaborately designed genetic algorithm. Specialized solution structure, decoders and penalty functions are utilized in the designed genetic algorithm.
Results
The genetic algorithm is proven effective and robust in solving the multi-period technology combination problem. The model output provides insights into what the fuel-efficient technology roadmap for 2016 and beyond would be. In the near term, the technologies of gasoline engines, which are cost-effective and sufficient in complying with the Phase IV standards, are still advantageous for OEMs. In the mid-term, plug-in hybrid electric vehicles (PHEV) and battery electric vehicles (BEV) would be introduced to the assortment to fill the standards compliance gap. Though available and effective in reducing FCR, diesel engine and corresponding technologies are not beneficial because of the costly technologies which are essential to satisfy more stringent future emission standards.
Limitations of this study
The life-cycle cost affected by the FCR of vehicles is not taken into consideration in this study, which would affect the utility of consumers and cause demand change.
What does the paper offer that is new in the field including in comparison to other work by the authors?
Complying with the CAFC standards is considered as combinational optimization problem and solved by genetic algorithm. Additionally, the roadmap of satisfying the standards is explored from the perspective of multiple periods.
Conclusions
Technologies of gasoline engines are cost-effective in the near term. OEMs in China should comply with the Phase IV CAFC standards mainly by optimizing gasoline engines. Meanwhile, OEMs should get prepared to introduce PHEVs and BEVs to satisfy the standards in 2020 and beyond.
Key Words : Corporate average fuel consumption, technology combination problem, genetic algorithm, technology roadmap