【作者】 刘天豪；

【导师】 柯坚；

【作者基本信息】 西南交通大学 ， 机械电子工程， 2011， 硕士

【摘要】 机液复合无级变速传动技术融合了机械传动和液压传动的优点,不仅能够实现无级变速的功能,而且可以增加无级传动的功率和提高传递效率,具有较广泛的应用前景。在国外,此项技术早在上世纪六、七十年代已得到商品化,在军用车辆和重型车辆上得到应用；而在国内,目前对机械液压复合传动技术的研究仍处于理论阶段,和国外相比有明显差距。因此,对其进行学习研究,对于提高我国在该领域的研究应用水平具有重要意义。文章首先分析了机液复合无级变速器(HMCVT)的工作原理及工作特性,并以东方红C702履带拖拉机为装机对象,设计了三段等差式机液复合无级变速器,以此为基础,主要进行了以下几个方面的工作：(1)详细分析工程车辆用柴油机的工作原理和特性,以实现发动机功率和负载功率的合理匹配、提高发动机的功率利用率为目的,制定了HMCVT系统的传动比控制方案,使其能够跟随负载变化而自动调节；(2).综合分析各种控制算法的优缺点及HMCVT的工作特点,设计开发了控制换段机构自动换段的“换段控制器”和控制变量泵排量跟随负载变化而自动调节的“自适应模糊PID控制器”；(3)采用仿真软件AMESim和Matlab/Simulink分别建立了HMCVT的结构模型及控制器模型,基于联合仿真技术对系统结构及控制器设计的合理性进行了仿真验证研究。仿真实验结果表明,本文设计的“换段控制器”和“自适应模糊P1D控制器”能够及时根据负载变化来自动调整系统传动比(自动换段或自动调节变量泵排量),达到了稳定发动机工作转速、实现发动机功率和负载功率合理匹配的目的。更多还原

【Abstract】 Hydro-mechanical Continuously Variable Transmission combines the advantages of mechanical transmission and hydraulic transmission, not only can realize the function of continuously variable transmission,but also can increase the transfer power and efficiency of stepless transmission, so it has a wider application. This technology has already beed commercialized in the 60/70 20th century in western countries, and was used on military vehicles and heavy vehicles. In China, the current study of HMCVT is still in theory stage, there were significant gaps compared to abroad. Therefore, the study and research in HMCVT has a great significance.This dissertation analyzes the working principal and operating characteristics of HMCVT, making the East Red C702 crawler tractor as an installed object, designed a three-segment/arithmetic type HMCVT. On this basis, the main work which have been done as follows:(1)Give a detailed analysis of the working principle and characteristics of the diesel engine used in construction vehicles, design the transmission ratio contorl program of HMCVT, which can realize the transmission ratio automatically adjust when the load changes, with the purpose of the best match between the engine power and the load power, and to improve the power efficiency of the engine;(2)Give a comprehensive analysis of the advantages and disadvantages of various control algorithms, and HMCVT work characteristics, design the "segment change controller" which can control the segment changes automatically and the "adaptive fuzzy PID controller" which can control the variable pump to change its displacement automatically;(3)Use AMESim and Matlab/simulink established the HMCVT structure model and controller model,use the combined simulation technology give a test study of the HMCVT structure and controller. Simulation results show that the "segment change controller" and "adaptive fuzzy PID controller" can work properly to adjust the transmission ratio (change the segment automaticaly or change the displacement of the variable pump automatically)when the load changes, the purpose of keeping the engine speed/realizeing the reasonable march between engine power and load power was achieved.更多还原