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The Study And Optimization About The Shift Schedule Of The Bus With Hydraulic Mechanical Automatic Transmission

Posted on:2014-07-03Degree:MasterType:Thesis
Country:ChinaCandidate:X ZhongFull Text:PDF
GTID:2252330425960094Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
Now the hydraulic mechanical automatic transmission is the leading product of automobile transmission system in the world, which has the ability of changing speed and the torque gradually and continuously. It also has the good self-regulation and adaptive ability to the external load. Owing to the advantages of comfortable, environment friendly, safety, energy saving, automatic transmission has a good development trend in the industry of bus. Now, in our country, most of the automatic transmissions using in the bus are Alison automatic transmission. It has two driving pattern. One is dynamic, the other is economic. However, the fuel consumption of the bus in city should be reduced as little as possible on the premise of meeting the requirement of arriving in every station on time. Therefore,the existing economic or dynamic shift schedule can’t meet the driving requirement well, they should be used in conjunction with each other. But the shift between the economic and dynamic shift schedule is inconvenient, what’s more, sometimes the driver may shift between the economic and dynamic shift schedule unreasonably.Considering the wide variation range of the load when it is running and the convenience of operation for the driver, the coefficient of colligation was introduced and a comprehensive shift schedule with the parameters of weight and throttle was proposed based on the traditional dynamic and economic shifting schedules by using Fuzzy control theory. Based on the software of MATLAB/Simulink, the comprehensive shift schedule structure was designed and simulated. Simulation results show that the shift point can be regulated automatically by using the comprehensive shift schedules based on the willingness and the actual load. On the premise of meeting the power requirement, the fuel consumption should be minimization. By this means, both of the dynamic and fuel economy had been achieved well. Besides, it is more convenient to drive.By analyzing the cause of shifting frequently or upshifting mistakenly in the city condition, or the special sections, such as braking or turning using the traditional shift schedule. We should increase the upshifting point and decrease the downshifting point real-timely and dynamically basing on the throttle, the change of the throttle and the actual weight of the bus by using the fuzzy control technology. In this way, it can adapt to the operation habit of different drivers by modifying the unreasonable operation, in order to avoiding shifting frequently or upshifting mistakenly. At the same time, the advantage of the traditional shift schedule have been retained. This fuzzy control algorithm don’t need extra sensors and can be debugged with little effort. What’s more, it has good applicability for the reason that it can be realized based on the existing platform.
Keywords/Search Tags:Hydraulic mechanical automatic transmission, Fuzzy Control, Overall shift schedule, intelligent-revised shift schedule
PDF Full Text Request
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