液压机械无级变速器自动变速控制系统研究

发布时间：2018-05-17 21:46

本文选题：液压机械无级变速器 + 发动机特性　；参考：《河南科技大学》2015年硕士论文

【摘要】：大功率高性能轮式拖拉机的需求不断增加,人们对其动力性、燃油经济性和操作舒适性的要求越来越高。液压机械无级变速器(HMCVT)能够实现高效率、大功率的传动。发动机和HMCVT作为拖拉机的核心部件,其性能直接影响着拖拉机的性能,同时发动机与HMCVT的匹配也影响着整车的性能。所以对发动机和变速器控制的研究对提高整车性能有着重要的意义。本文首先建立了发动机的数学模型,发动机模型清楚地表达了发动机的性能。分析了发动机的特性曲线,得出了发动机的动力性能指标和经济性能指标随转速变化的规律,以及发动机的最佳经济性和最佳动力性工作曲线。以400马力轮式拖拉机HMCVT为研究对象,分析了多段HMCVT的速比特性、转矩特性、功率分流特性及效率特性,进一步研究了HMCVT传动拖拉机的牵引特性分析计算原理和表达方法,根据HMCVT速比变化特点,对发动机和变速器进行匹配,得出了在发动机的最佳经济性和最佳动力性的情况下,HMCVT经济性和动力性目标段位对应的目标速比。分析了变速器自动变速控制系统的控制原理以及液压控制单元各部件的功能,确定了电子控制系统的组成部分,针对该控制系统设计了基于TMS320F2812数字信号处理系统的硬件电路,主要设计了DSP的最小系统,信号的输入输出模块以及通讯模块等硬件电路。确定了软件控制模块的控制算法,采用matlab建立了泵-马达的控制系统模型,仿真证明了模糊PID控制比普通PID控制的优越性。针对自动变速控制功能的部分程序进行了设计,最后验证了控制系统的可行性。
[Abstract]:With the increasing demand of high power and high performance wheeled tractors, the demand for power, fuel economy and operating comfort is becoming higher and higher. Hydraulic mechanical stepless transmission (HMCVT) can achieve high efficiency and high power transmission. As the core component of tractor, engine and HMCVT have a direct impact on the performance of tractor, and the matching between engine and HMCVT also affects the performance of the whole vehicle. Therefore, the study of engine and transmission control is of great significance to improve the vehicle performance. In this paper, the mathematical model of the engine is established, and the performance of the engine is clearly expressed by the engine model. The characteristic curve of engine is analyzed, and the variation law of engine dynamic performance index and economic performance index with rotating speed, as well as the optimum economy and power performance curve of engine are obtained. Taking HMCVT of 400hp wheeled tractor as the research object, the speed ratio characteristic, torque characteristic, power shunt characteristic and efficiency characteristic of multi-segment HMCVT are analyzed, and the principle and expression method of traction characteristic analysis and calculation of HMCVT tractor are further studied. According to the changing characteristics of HMCVT speed ratio, the target speed ratio of engine and transmission is obtained under the condition of the best economy and the best power performance of the engine, and the target speed ratio corresponding to the economic and dynamic target segments of the engine is obtained. This paper analyzes the control principle of transmission automatic speed change control system and the function of each component of hydraulic control unit, determines the component of electronic control system, and designs the hardware circuit based on TMS320F2812 digital signal processing system for the control system. The minimum system of DSP, the input and output module of signal and the communication module are designed. The control algorithm of the software control module is determined and the control system model of the pump motor is established by using matlab. The simulation results show that the fuzzy PID control is superior to the ordinary PID control. Finally, the feasibility of the control system is verified.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S219;TH137

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