【作者】 具大源；

【导师】 胡树根； 王耘； 宋小文；

【作者基本信息】 浙江大学 ， 机械工程， 2012， 硕士

【摘要】 机油冷却器是汽车内燃机中润滑系统的重要部件之一,是一种加速润滑机油的散热而使其保持较低温度的装置,其质量的好坏对发动机的运行效果有着重要的影响。通常机油冷却器处在恶劣的工作环境下,因此对其进行疲劳试验对于保证其正常工作有着非常重要的意义。目前广泛使用的一种对机油冷却器进行疲劳试验的方法是通过采用电液比例技术来对其进行疲劳脉冲实验,该方法主要通过调整比例溢流阀的阀口开度来控制试件容腔内液体的压力来模拟各种周期压力信号(如正弦波,三角波,梯形波),从而对试件进行多次压力冲击来检验其疲劳性能。为了更好的提高控制系统的压力跟踪精度和适应性,本文设计了一种基于鲁棒重复控制的机油冷却器脉冲疲劳试验台控制系统。本论文的主要工作内容如下：(1)分析了机油冷却器的主要功能,疲劳试验台的工作原理以及对机油冷却器进行疲劳试验的必要性。介绍了电液比例技术的发展状况以及电液比例技术中采用的控制策略。(2)介绍了重复控制、鲁棒重复控制的基本原理以及鲁棒重复控制器的设计方法和步骤,明确了鲁棒重复控制器设计中的关键问题和设计策略。(3)确定了系统的设计方案以及技术路线,按照DCS的思想设计了机油冷却器脉冲疲劳试验台的硬件环境并说明了系统的工作原理。分析了系统硬件执行元件的放置方式。搭建了系统的软件环境,说明了软件的工作流程。(4)根据液压的相关知识建立了比例溢流阀的数学模型,并根据所提出的数学模型设计了鲁棒重复控制器。(5)在Matlab/Simulink中建立了鲁棒重复控制器、重复控制器以及PID控制器的仿真模型。将PID控制器与重复控制器,重复控制器与鲁棒重复控制器进行比较,验证了所设计的鲁棒重复控制器对于压力跟踪的精确性；修改了系统的参数,验证了鲁棒重复控制器对于系统参数变化的鲁棒性；改变了输入信号的周期,并对比了鲁棒重复控制器和重复控制器对于改变了周期的输入信号的跟踪情况,说明了鲁棒重复控制器对于周期信号变化的适应性。(6)根据重复控制器和鲁棒重复控制器的对比结果,总结了重复控制和鲁棒重复控制对于跟踪周期信号的共同点和不同点,进一步说明了所设计的鲁棒重复控制器的优越性。(7)将所设计的鲁棒重复控制器进行离散化,并在计算机上编程实现了该控制算法,验证了鲁棒重复控制的控制效果。更多还原

【Abstract】 Oil cooler is one of the most important components in Automobile Internal Combustion Engine’s lubrication system. It is a device which is used to accelerate the radiation of the lubricant to keep it at low temperature. The operational effect of I.C. Engine is largely depended on the quality of oil cooler.More often than not, oil cooler is working under severe conditions. Therefore it is essential to implement some fatigue tests before oil cooler is used on the real system to ensure that it can work properly. Currently, one of the most widely-used methods is to use electro-hydraulic technology to put such experiments into practice, which simulates various kinds of periodical pressure signals by adjusting the opening of the pressure relief valve. By repeating different types of periodical pressure shocks (sine wave, triangular wave, trapezium wave, etc) on the specimen, the fatigue property of oil cooler could be tested. With the purpose to improve the pressure tracking accuracy and the adaption of the control system, this paper designed an oil cooler’s fatigue pulsation test-bed system based on robust repetitive control theory.The main content of this paper is as follows:1. Analyze the main function of oil cooler, the working principle of fatigue pulsation test-bed and the necessity to execute fatigue experiments. Give a brief introduction to the development of electro-hydraulic technology and control strategies adopted in it.2. Introduce the basic principle of repetitive control and robust repetitive control and the methods to design them, clarify the key problems and design strategies of robust repetitive control.3. Determine the design scheme and technical route of the whole system, design the hardware and software environment of the oil cooler’s pulsation test-bed according to the concept of DCS, illustrate the working principle of the hardware system and the working process of software system. Analyze the layout of the hardware execution components.4. Propose the mathematical model of the pressure relief valve according to the knowledge of hydraulic and design robust repetitive controller of test-bed based on the proposed model.5. Build up simulation models of PID controller, repetitive controller and robust repetitive controller in Matlab/Simulink environment. Prove the accuracy of pressure tracking of the designed robust repetitive controller by comparing tracking effects of PID controller, repetitive controller and robust repetitive controller. Testify the robustness of the designed robust repetitive controller to parameter variations by modifying the parameter of the pressure relief valve. Confirm the adaption of the designed robust repetitive controller to periodical signal variations by altering the period of input signal and comparing the effects of repetitive controller and robust repetitive controller.6. Summarize the similarity and difference of repetitive control and robust repetitive control in tracking periodical signals according to the comparing results and verify the priority of the designed robust repetitive controller.7. Discrete the designed robust repetitive controller and then fulfill it on the real system by writing program on the computer. Prove the effectiveness of robust repetitive controller.更多还原