【作者】 程文芳；

【导师】 刘银水；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2008， 硕士

【摘要】 液压同步控制系统具有结构简单、组成方便、易于实现自动控制、适宜较大功率场合等优点,在许多领域具有广泛的应用。传统的液压同步控制系统均以矿物油作为工作介质,在安全和环保要求严格的场合其应用受到限制。水液压技术具有绿色环保、抗燃安全等突出优点,是当前国际上流体传动领域的研究前沿。在某些安全和环保要求高的场合,如食品机械、水上舞台、海洋工程等,用水压驱动取代油压驱动进行同步控制,具有广泛的应用前景。本文基于目前国内外水压技术发展的状况,特别是相关水压比例/伺服控制元件的选择受到限制的情况下,搭建了一种水压比例调速阀控制的位置同步系统,并对该系统的控制、测量方法进行了研究,论文的主要研究内容如下:分析了双缸位置同步控制系统的类别和各自的特点。选定控制策略为串联型控制。该系统是带反馈的位置同步控制系统,主动缸由手动型单向水压节流阀控制,从动缸由水压比例调速阀控制。通过分析得出从动缸进出口双阀的控制信号之比等于活塞两端的面积之比。研制了同步控制系统的执行元件——水压缸。为了保证同步系统的控制性能,减小水压缸的摩擦力是一个关键问题。本文在分析水压缸摩擦机理的基础上,提出了减小摩擦力,防止低速爬行的措施;对水缸的泄漏,腐蚀及工艺等问题,提出了防范措施。水压缸的样机试验表明,上述减小摩擦力的措施行之有效,缸的性能达到了设计指标要求。对水压比例调速阀、水压缸以及由它们组成的同步控制系统进行了数学建模,并对数学模型内的参数选取进行了说明。利用MATLAB/SIMULINK工具箱构造了实时仿真模型,对水压缸的固有频率及阻尼系数影响因素进行了分析;获取模型的响应,考察了系统的动静态响应特性。更多还原

【Abstract】 The hydraulic position synchro systems have many advantages such as simple structure, easy to buildup, easy to control by automation and output power is great. So the hydraulic system has wide applications in many fields. The traditional hydraulic systems use oil as the work medium and are restricted for the purpose of safety and cleanness. Water hydraulic system is anti-burning and more safety and clean to environment. It’s one of the develop directions of current international fluid transmission field. It can replace the oil hydraulic system in some occasions which has high requirements of anti-fire and environment protection, for examples the food production, upper water stage and sea engineering. It has a wide prospect.This thesis makes a research on development of water hydraulic technology and buildup a water hydraulic position synchronizing system in the condition that water hydraulic control valves are limited. It also studies on the control theories and testing methods of the system. The main works of this thesis include:This thesis points out that the system is actually a position control system with position feedbacks. It classifies position synchro systems to several kinds and analyzes the characteristics of them. The system’s two cylinders are controlled separately. One is controlled by Danfoss’s manual throttling control valve and the other one by two Danfoss’s proportional flow control valves. The latter cylinder should follow the former. The two proportional valves’input signals are also discussed in the thesis.Design of the low friction cylinder which will be used in this system is done. In order to obtain high performance, the low friction is essential for cylinder. The thesis studies on the friction phenomenon and some improvements are put forwards to reduce friction and stick-slip of the piston. Some strategies are pointed out to solve the leakage, corrosion and low lubricant problems of water hydraulic cylinder in thesis. A test is made and the result shows the cylinder works normally and has low friction.The mathematical models of the flow control valves, cylinder and the whole control system are built. Some parameters of these models are expatiated. The relating real-time simulations are built by using the MATLAB/SIMULINK toolbox. The simulating result shows factors which influence the natural frequency and damping factor of cylinder. The static and dynamic characteristics of control system are also get from simulating models.更多还原