Emission Quality Evaluation And Fault Diagnosis Of Internal Combustion Engine In Plateau

China is endowed with large scale of plateau and magnificent landscape.The protection of the ecological environment is fundamental requirement for quality development of plateau cities in the new era.The number of car ownership in plateau cities is increasing by year,and it has been one of the key air pollution sources in the plateau.Meanwhile,internal combustion engine(ICE)is the core of a vehicle.There is a significant increase of fault rate under the plateau conditions and it brings about a more severe situation of exhaust pollution,which poses a large security threat.Therefore,as for consumers in plateau cities,there is an increasing demand for safety,environmental friendliness and intelligent diagnosis capability,which will be future focus of ICE market competition.Hence,to conduct a study of ICE emission quality evaluation and operational intelligent decision knowledge base is significant for the development of Kunming Yunnei Power Co.,Ltd(Yunnei Group),environmental protection of plateau cities and the ICE highland preempt.This paper,based on the experimental platform of Yunnei Group,takes a dual perspective from ecological environment protection and optimized product design to explore the quality enhancement of ICE plateau emission,fault diagnosis and operational intelligent decision on this basis of exhaust data.Main research contents include four core parts.(1)Statistic analysis of ICE plateau emission features.Small bore engine has significant advantages in emission and cost,and it is the focus in future market competition.It is the key sales of Yunnei Group.This study takes small bore engines as the research objective to conduct experiments of ICE plateau emission,and presents a statistic analysis of exhaust emission features under the standard and fault circumstances to investigate whether altitude has the effects on exhaust emission.(2)A comprehensive evaluation of ICE emission quality.We adopt intervals to measure the levels of pollution,employ probability theory to calculate the objective attribute weight and rough set theory to determine the subjective attribute weight to build a fuzzy set evaluation model of ICE emission quality.Finally,case data are used to verify the validity of this method and comparison of altitude effects are made to discuss the effectiveness of different emission reduction projects.(3)Intelligent diagnosis model of ICE faults.We propose a new ICE fault diagnosis model based on IHS-RVM.To acquire a RVM diagnosis model with better performance,we make improvements on the acquisition of three parameters HMCR,PAR and BW in Harmony Search(HS),i.e.,the improved harmony search(IHS),and we use exhaust information to build the IHS-RVM fault diagnosis model.(4)Intelligent evaluation knowledge base design of ICE plateau emission.Firstly,expressions of knowledge base are designed.According to exhaust information and operational status relationship,we build the regulation base,fact base and expert base for the intelligent evaluation of ICE plateau emission.Meanwhile,to enhance the capability of the knowledge base,we make the maintenance data dictionary and knowledge index module,which lays the foundation for the intelligent evaluation baseThe novelty of this research is mainly embodied in the following aspects.(1)It provides a testing scheme of IC engine exhaust emission under different operation status with varying altitudes.This research takes Yunnan Province,whose elevation gain between the highest altitude and the lowest altitude falls over 6000 meters,as the testing province in the scheme;typical cities with the plateau features are chosen as the example;testing error are minimized with the control of altitude and operation.This scheme tackles the difference of testing data and actual operation data,and reveals the exhaust emission capability and basic rules of IC engine at different altitudes.(2)It offers a quality evaluation method of ICE plateau emission and builds a fault diagnosis knowledge base of ICE exhaust information.In this paper,we propose a fuzzy set evaluation model of ICE emission quality based on combined weight,which integrates multi-disciplinary knowledge such as quality management,fuzzy mathematics,mechanic engineering and so on,to cope with the shortage of qualitative evaluation.Meanwhile,a combination of rough set,harmony algorithm and RVM methods is used to apply corresponding advantages of attribute reduction,parameter optimization and learning prediction,which clarifies the matching relations between ICE plateau fault features and exhaust information.Under the guidance of intelligent decision-making knowledge system theory,ICE fault diagnosis knowledge base is constructed to cope with the low accuracy and low effectiveness.