电液流量、方向连续控制新原理及其应用研究

发布时间：2018-06-12 08:42

本文选题：比例方向阀 + 流量反馈　；参考：《太原理工大学》2013年博士论文

【摘要】：电液控制技术在航空、航天,海洋工程、冶金,矿山、重型机械等体现一个国家综合国力和国防现代化的许多工业领域,起着非常关键的作用。这一技术的核心是控制执行器工作速度、方向、位置和输出力的流量、方向连续控制元件,目前主要有比例方向阀和伺服比例阀。这一领域,我国虽然在系统集成技术方面已取得了许多成就,但在核心元件技术方面同国外发达国家仍有较大差距,制约了我国装备制造业的发展,许多国家需求的重大装备,如全断面掘进机、板坯连铸连扎设备、大型成型设备等,所用电液控制元件,特别是高性能比例方向阀、伺服比例阀只能高价从国外进口,造成国外在技术和价格上对我国的垄断。国家也充分认识到这一问题的严重性,2009年5月国务院出台的装备制造业调整和振兴规划,在原有振兴装备制造业16个优先发展重大专项基础上,补充了基础部件,这其中就包含电液伺服和比例元件。在我国制定的国家中长期科学和技术发展规划纲要(2006—2020年),优先主题第26项之基础件和通用部件：“重点研究开发重大装备所需的关键基础件和通用部件的设计、制造和批量生产的关键技术”,更是将电液控制技术所需的核心元器件列为重点研发内容。正是在这样的背景下,在国家自然科学基金“有源、流量闭环先导级为驱动的电液流量控制理论与方法、51175362”和国家2011年重大科技成果转化项目“高响应、大流量伺服比例阀关键技术、系列产品开发及应用”的资助下,提出本课题的研究内容,通过对新的电液流量控制方法相关基础问题的研究,为我国自主研发高精度、高动态响应、模块化、易集成的比例流量控制元件提供理论和试验依据。首先,对国内外的相关研究工作作了较为详细的分析和论证,找出了现有技术存在的不足,提出解决问题的创新思想,研究工作对发展具有我国自主知识产权的低能耗电液流量控制元件,突破国外在这一领域对我国技术和经济上的垄断及制约,带动我国液压工业发展,推动相关主机行业的技术进步具有重要的理论和现实意义。对影响电液伺服比例阀特性的关键技术和基础理论开展了研究,采用流体动力学仿真方法CFD,对影响阀特性的动静态液动力及其补偿方法作了研究,给出了新的减小液压动力影响的补偿方法；对制约阀动态响应快速性的电机械转换器及其控制方法作了研究,提出采用动圈式电机械转换器做驱动的改进思路。提出创新的比例方向阀控制方案,对新型比例方向阀的工作机理进行阐述,对关键的结构参数进行设计、计算,应用AutoCAD软件和Pro/E软件详细建立了阀的二维工程图和三维实体模型,验证了结构参数的合理性,为后续仿真优化设计、工作特性分析以及生产物理样机奠定了基础。根据新型比例方向阀的结构及工作原理,建立阀的完整数学模型。根据线性化理论,对阀的动静态特性进行理论计算和分析,对影响稳态控制特性及零位阀系数的主要几何参数展开讨论；根据合理假设,进一步将阀的非线性状态空间模型简化,推导出系统方框图和传递函数,并对系统稳定性进行分析,得出了新型比例方向阀的系统稳定性条件。研究结果表明,阀的动态特性为一阶滞后环节,其转折频率随节流槽面积梯度的增大而增大,随阀芯面积比的增大而减小。为保证阀的稳定性,节流槽应留有一定的预开口量。将阀的CAD实体导入SimulationX仿真平台,创建出新型比例方向阀的多学科仿真模型,分别在时域和频域中对阀的稳态特性和动态特性进行仿真研究,讨论了将先导阀回油直接引油箱以及节流槽面积梯度的改变对阀的动态性能影响。研究结果表明,新型比例方向阀的稳态特性和等位移特性良好,主阀芯位移控制曲线的线性度也较好,但有一定的中位控制死区。阀的动态阶跃响应时间较长,阀芯位移的响应速度与系统压力和给定信号有关。阀的工作频宽约7Hz,频响曲线没有出现谐振峰值,具有典型一阶滞后环节的特征,仿真结果验证了理论分析的正确性。为进一步提高阀的控制精度和动态性能,提出采用主阀芯位移-电闭环、先导阀芯位移-电闭环和双电闭环三种控制方案,分析了三种阀的结构特点及工作机理,分别对其进行多领域建模和仿真研究。结果表明,主阀芯位移-电闭环控制阀能够明显抑制液动力、摩擦力等干扰,提高了阀的稳态控制精度和动态响应速度,将阀的频带拓宽到18Hz,阀的综合性能获得大幅度提升；采用先导阀芯位移-电闭环控制,由于系统闭环包括的范围太小,无法消除功率级干扰,因此对阀的性能影响不大；加入双电闭环控制则可以结合前两种电闭环控制的优势,合理调节控制器参数,就可使阀获得最佳的工作特性。引入电闭环控制方案,不仅改善了阀的动静态性能,也使阀具有了在闭环控制通道发生故障的情况下,仍可开环工作的容错控制功能。
[Abstract]:Electro-hydraulic control technology plays a very important role in many industrial fields, such as aeronautics, spaceflight, marine engineering, metallurgy, mine, heavy machinery and so on, which embodies a national comprehensive national strength and the modernization of national defense. The core of this technology is to control the speed, direction, flow of position and output force of the actuator and the direction of continuous control components. There are proportional directional valves and servo proportional valves. In this field, although many achievements have been made in system integration technology in China, there is still a big gap between the technology of core components and the developed countries in foreign countries, which restricts the development of our equipment manufacturing industry and the major equipment for many countries, such as full section tunnelling machine, slab continuous casting and continuous ligation. Equipment, large molding equipment, electro-hydraulic control elements, especially high performance proportional directional valves, and servo proportional valves can only be imported from abroad, resulting in foreign monopoly on technology and price. The state is fully aware of the seriousness of this problem. In May 2009, the State Council issued the adjustment and revitalization of the equipment manufacturing industry. The basic components are supplemented on the basis of 16 major development priorities for the revitalization of the equipment manufacturing industry. This includes electro hydraulic servo and proportional components. The national medium and long term science and technology development program (2006 - 2020), the basic components and general components of the twenty-sixth priority themes in China, are made in China: "key research and development are important." The key technologies for the design, manufacture and mass production of the key basic components and general components required for equipment are listed as the key components of the electrohydraulic control technology. It is in this context that the theory and side of the "active, flow closed lead level" driven by the National Natural Science Foundation of the national Natural Science Fund (National Natural Science Foundation) Law, 51175362 "and the national 2011 major scientific and technological achievements transformation project" high response, the key technology of the large flow servo proportional valve, the development and application of a series of products ", put forward the research content of this topic, through the research on the basic problems related to the new method of electrohydraulic flow control, high precision and high dynamic response for our country's independent research and development. Modular and easily integrated proportional flow control components provide theoretical and experimental basis.
First, we make a more detailed analysis and demonstration of the relevant research work at home and abroad, find out the shortcomings of the existing technology, put forward the innovative ideas to solve the problems, and develop the low energy consumption control elements with our own intellectual property right in the research work, and break through the monopoly of China's technology and economy in this field. It is of great theoretical and practical significance to promote the development of China's hydraulic industry and promote the technological progress of the relevant host industry.
The key technology and basic theory affecting the characteristics of electro-hydraulic servo proportional valve are studied. The hydrodynamic simulation method CFD is used to study the dynamic and static hydrodynamic force of the valve and its compensation method. A new compensation method for reducing the influence of hydraulic power is given, and the electrical and mechanical conversion of the dynamic response of the valve is made. The device and its control method are studied, and the improvement idea of using moving coil electromechanical converter to drive is proposed.
A new proportional directional valve control scheme is proposed. The working mechanism of the new proportional directional valve is expounded. The key structural parameters are designed and calculated. The two dimensional engineering drawing and three-dimensional solid model of the valve are established in detail by using AutoCAD software and Pro/E software. The rationality of the structural parameters is verified, and the work is optimized for the follow-up simulation. Characteristics analysis and production of physical prototype laid the foundation.
Based on the structure and working principle of the new proportional directional valve, a complete mathematical model of the valve is established. Based on the linearization theory, the dynamic and static characteristics of the valve are theoretically calculated and analyzed. The main geometric parameters affecting the steady state control and the zero valve coefficient are discussed, and the nonlinear state space model of the valve is further studied. The system's block diagram and transfer function are derived, and the stability of the system is analyzed. The stability conditions of the new proportional directional valve are obtained. The results show that the dynamic characteristics of the valve are first order lag link, and the turning frequency increases with the increase of the area gradient of the slot area, and decreases with the increase of the area ratio of the valve core. The stability of the valve should be kept at a certain amount of pre opening.
The CAD entity of the valve is introduced into the SimulationX simulation platform, and a multi-disciplinary simulation model of the new proportional directional valve is created. The steady-state and dynamic characteristics of the valve are simulated in the time domain and frequency domain respectively. The influence of the change of the change of the pilot valve back oil direct fuel tank and the area gradient of the throttle area to the dynamic performance of the valve is discussed. The results show that the steady state and equal displacement characteristics of the new proportional directional valve are good, and the linearity of the main valve core displacement control curve is also good, but there is a certain middle position control dead zone. The dynamic step response time of the valve is longer, the response speed of the valve core displacement is related to the system pressure and the given signal. The frequency width of the valve is about 7Hz and the frequency response curve is not The resonance peak has the characteristics of typical first order delay. The simulation results verify the correctness of the theoretical analysis.
In order to further improve the control precision and dynamic performance of the valve, three control schemes are proposed, which are the main valve core displacement electric closed loop, the pilot valve core displacement electric closed loop and the double closed loop control scheme. The structure characteristics and working mechanism of the three valves are analyzed and the multi domain modeling and simulation research are carried out respectively. The results show that the main valve core displacement electric closed loop control valve is carried out. It can obviously restrain the interference of fluid power and friction, improve the steady state control precision and dynamic response speed of the valve, widen the valve's frequency band to 18Hz, and improve the comprehensive performance of the valve greatly; with the pilot valve core displacement electric closed loop control, the power level interference can not be eliminated because the closed loop of the system is too small to eliminate the power level interference. Therefore, the valve can not be eliminated. The performance of the double closed loop control can be combined with the advantages of the first two kinds of closed loop control, and the optimal control parameters can be adjusted to make the valve get the best performance. The electric closed loop control scheme is introduced, which not only improves the dynamic and static performance of the valve, but also makes the valve with the failure of the closed loop control channel. The fault-tolerant control function of open loop work.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TP271.31

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