并联型先导控制电液伺服阀的数学模型及控制算法研究

发布时间：2018-06-24 01:19

本文选题：并联先导级 + 数学模型　；参考：《浙江大学》2012年硕士论文

【摘要】：随着电液伺服系统在重大装备中的广泛应用,对大流量电液伺服阀的快响应指标的要求越来越高。采用传统串联型先导控制结构的伺服阀在解决“大流量”与“高频响”这对矛盾时,遇到了难以逾越的困难。而并联型伺服控制方案已成为解决该问题的重要研究方向。其中,基于并联型先导控制的伺服阀是解决该矛盾最有效的解决方案。基于并联型先导控制原理,建立并联型先导控制电液伺服阀的准确仿真模型,对并联型先导级的非对称参数匹配和基于并联先导级的伺服阀主级位置闭环分段非线性协同控制方案进行了仿真与试验研究。研究表明,此方案可同时实现大流量高频响伺服阀在两个工作点之间大范围跳变的阶跃响应和在一个工作点附近的高频调整频率响应性能指标的优化,为我国大流量、高频响电液伺服技术的新发展奠定了重要的理论基础,并进一步地拓宽了电液伺服阀的应用领域。论文的第一章在简要介绍电液伺服阀在现代电液控制系统中实现大流量、高频响的迫切性的基础上,分析了电液伺服阀在实现大流量和高频响之间出现的矛盾,并指出了其技术难点。通过对电液伺服阀在大流量、高频响以及相关控制方法方面的研究现状的分析,更进一步明确了该课题的研究意义与价值；最后,提出了本课题的研究目标与主要研究内容,使以后的研究工作明确了研究思路。论文的第二章对并联先导控制电液伺服阀的组成及各部分工作机理进行了详细的分析,建立了各主要组成部分的数学模型并推导出传递函数,最后得出研究对象的频域数学模型,根据数学模型在理论上分析了一些参数对主阀动态特性的影响。最后,基于AMESim仿真软件建立了研究对象的仿真模型,并通过试验验证了仿真模型在时域和频域的正确性,为后续的研究分析奠定了基础；论文的第三章基于仿真模型对管道参数和蓄能器参数对主阀动态特性的影响进行了仿真分析,得出了一些结论,并利用遗传算法对参数的匹配性进行优化设计；采用FLUENT软件对主阀液动力进行了仿真计算,并将对应的液动力系数应用于AMESim仿真模型中,并对外流式和内流式的液动力情况进行分析,得出了内流式时液动力较小的定性结论,结合主阀工作压差变化大的特性对分析了稳态液动力随阀口压降变化的变化情况；基于AMESim仿真模型,提出了解决主阀在开启阶段B口上压时阀芯出现震荡现象的问题和并联先导阀组零位漂移现象引起的控制特性不可靠问题的解决方案；论文的第四章分析了流量增益、流量——压力系数和压力增益三个系数对系统控制特性的影响,基于仿真模型对分段线性控制和分段非线性控制两种控制方法的控制特性做了仿真研究,提出分段非线性的控制方法是解决高频响大流量矛盾的最有效控制方法。介绍了主级闭环分段非线性控制的控制策略和控制方案,基于仿真模型确定了主阀在大范围调整到小范围调整的切换点最优值,为后续的实验研究奠定了基础。为了对并联先导控制大流量电液伺服阀进行试验研究,搭建了大流量阀测试试验台。论文的第五章对大流量阀测试实验台和试验方法做了简单介绍,试验方法上采用matlab与NI数据采集卡通讯实现数据处理,采用matlab_xpc系统对测试系统实时控制；将分段非线性控制方法应用于并联先导控制电液伺服阀的试验研究,主要对主阀的阶跃响应特性、频响特性和滞环特性进行了试验研究,重点验证了仿真模型在时域和频域的正确性以及仿真模型中的出的结论的正确性。论文的第六章对本课题已完成的研究情况作了全面的总结,并指出了在研究工作中存在的问题,提出了以后应开展的研究工作的重点。
[Abstract]:With the extensive application of the electro-hydraulic servo system in the important equipment, the demand for the fast response index of the large flow electro-hydraulic servo valve is getting higher and higher. The servo valve with the traditional series pilot control structure has encountered difficulties in solving the contradiction between the "large flow" and "high frequency". The parallel servo control scheme has already been encountered. The servo valve based on parallel pilot control is the most effective solution to the problem. Based on the parallel pilot control principle, the accurate simulation model of the parallel pilot controlled electro-hydraulic servo valve is established, and the asymmetrical parameter matching of the parallel pilot stage and the parallel pilot grade are based on the parallel pilot control principle. The simulation and Experimental Research on the closed-loop piecewise nonlinear cooperative control scheme for the main position of the servo valve are carried out. The study shows that the scheme can simultaneously realize the step response of the high frequency high frequency sound servo valve in large range between two working points and the optimization of the frequency response performance index near a working point for our country. The new development of large flow and high frequency electro hydraulic servo technology has laid an important theoretical foundation and further widened the application field of electro-hydraulic servo valve.
On the basis of the urgency of realizing large flow and high frequency noise in modern electro-hydraulic control system, the first chapter of the paper analyzes the contradiction between the high flow and high frequency response of the electro-hydraulic servo valve, and points out its technical difficulties. Through the high flow, high frequency response and the related control side of the electro-hydraulic servo valve in the electro-hydraulic servo valve. The analysis of the present research status of the law further clarifies the significance and value of the research. Finally, the research objectives and main research contents are put forward, which makes the research work clear in the future.
The second chapter of the paper makes a detailed analysis of the composition and working mechanism of the electro-hydraulic servo valve with parallel pilot control, establishes a mathematical model of the main components and derives the transfer function. Finally, the mathematical model of the frequency domain of the research object is obtained. The mathematical model is used to analyze the dynamic characteristics of the main valve according to the mathematical model. Finally, based on the AMESim simulation software, the simulation model of the research object is set up, and the correctness of the simulation model in the time and frequency domain is verified by the experiment, which lays the foundation for the subsequent research and analysis.
The third chapter of the thesis is based on simulation model to simulate the influence of pipe parameters and accumulator parameters on the dynamic characteristics of the main valve. Some conclusions are obtained, and the genetic algorithm is used to optimize the matching of the parameters. The FLUENT software is used to simulate the hydraulic power of the main valve, and the corresponding hydraulic coefficient should be calculated. In the AMESim simulation model, the fluid dynamic situation of the external flow and the internal flow is analyzed. The qualitative conclusion of the small hydrodynamic force in the inner flow is obtained. The change of the steady liquid power with the pressure drop of the valve port is analyzed with the characteristics of the main valve working pressure difference. Based on the AMESim simulation model, the solution of the main valve is proposed. In the early stage, the problem of oscillation of the spool on the B port and the solution to the unreliable control characteristic caused by the zero drift of the parallel pilot valve group are discussed.
The fourth chapter of the paper analyzes the influence of the flow gain, the flow rate, the pressure coefficient and the pressure gain on the control characteristics of the system. Based on the simulation model, the control characteristics of the two control methods of piecewise linear control and piecewise nonlinear control are simulated, and the piecewise nonlinear control method is proposed to solve the high frequency loud and large flow. The most effective control method of the quantity contradiction is introduced. The control strategy and control scheme of the main level closed loop piecewise nonlinear control are introduced. Based on the simulation model, the optimal value of the switching point for the main valve to be adjusted in a large range to a small range is determined, which lays a foundation for the subsequent experimental research.
In order to test and study the large flow electro-hydraulic servo valve with parallel pilot control, a test test rig for large flow valve is set up. The fifth chapter of the paper introduces the test test bed and the test method of the large flow valve. The test method adopts the communication of MATLAB and NI data acquisition card to realize the data processing, and the test system is adopted by the matlab_xpc system. The piecewise nonlinear control method is applied to the experimental study of a parallel pilot controlled electro-hydraulic servo valve. The step response characteristics, frequency response characteristics and hysteresis characteristics of the main valve are studied. The correctness of the simulation model in the time and frequency domain and the conclusion of the simulation model are verified.
The sixth chapter of the paper makes a comprehensive summary of the research situation that has been completed, and points out the existing problems in the research work, and puts forward the focus of the research work that should be carried out in the future.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH137.52

【参考文献】