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Study On Fuzzy Logic Control Strategy Of Parallel Hybrid Electric Vehicle

Posted on:2008-07-02Degree:MasterType:Thesis
Country:ChinaCandidate:S M MingFull Text:PDF
GTID:2132360212496439Subject:Vehicle Engineering
Abstract/Summary:PDF Full Text Request
Hybrid technology has been taken as one of the most promising technologies for clean vehicles through world wide. Since this century, China has put a lot of efforts to enhance the commercialization process of hybrid electric vehicles, in order to save energies and decrease pollutions. Under these circumstances, the study on Hybrid Electric Vehicle (HEV) control technology which is one of the key technologies of hybrid electric vehicles and embodiment of independent intelligent property right is becoming more and more important. Based on the development of the HEV, this thesis introduced the recent research on the control strategies of parallel HEV to the all-sized and embedded research.The most familiar control strategy in parallel HEV is logistic threshold value. This control strategy is highly code conversion and concise. So it can get better control effect under the condition that engine's and motor's characteristic and the drive cycle are defined. But this adaptive ability of control strategy is not so good because the thresholds have already been set and they are fixed values can not be changed. So this control strategy can not make sure engine work at better region if conditions changed. For these reasons, the logistic threshold value has some limits at the HEV's fuel economy. So we need study another control strategy.HEV control strategies had been analyzed in this thesis and then summerrized the form of control strategies and control targets. Logic threshold control strategy and fuzzy logic control strategy have been choosed for simulationand analysis of parallel HEV. The main contents are as follows:Firstly the thesis analyzes the importants of HEV control strategy research in detail, putting forward the concept of control target, categorizing elucidation the HEV control strategy from the angle of these control targets existed, at the same time this thesis involves the current control strategy for a brief introduction. Based on a systematic study of control strategies for hybrid power train this thesis lists block-diagrams of control strategies separately, preparing for establishing and simulating the logic threshold control strategy and fuzzy logic control strategy forthe parallel hybrid power train.Secondly the thesis introduces the design flow and the results of the simulation systemically. Study control strategy for parallel and establish a simple and practical control method, using logic threshold value and achieving the best fuel economy and emission performance of vehicle. According to the different control parameters these control strategies should be devided to four control strategies.Fuzzy control is based on experiences, it is no need to know the math model which is in charge of, and it is easy to control the system not identified or non-linear, and is robust to an uncertainty system, and it can get rid of external noise. Fuzzy logic control has been widely used in the field of HEV, and the result of research can manifest the bright future of fuzzy logic control. The design and research of parallel HEV fuzzy logic control strategy is based on parallel HEV driving system and HEV logic threshold control strategies, using the fuzzy logic control to complete the design of control algorithm. In this thesis, fuzzy logic control strategy has been systematically introduced and builded fuzzy logic control system for parallel HEV. Fuzzy logic control strategy according to different control target is designed and the simulation of the fuzzy logic control strategy is analysized in this thesis.Control strategy can decide the state of all the components, and also decide the driving ability, economic ability. Meanwhile, all the different ways to realize the control strategy induce the controller needs different hardware to be finished, which has a grate influence on the controller's practical use, so the analysis between control strategies is very complex but also important.This thesis analyses the logic threshold control strategy and fuzzy logic control strategy of parallel HEV. The control strategy not only analyses performance but also the character of theirs. The simulation results of fuzzy logic control strategy and logic threshold control strategy, according to the way of realizing the control targets, robust to conclude that the necessary and importance of parallel HEV fuzzy logic control strategy.
Keywords/Search Tags:hybrid electrical vehicle, control strategy, logic threshold, fuzzy logic, fuel economy
PDF Full Text Request
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