基于可拓控制策略的材料试验机电液比例控制系统的研究

【作者】 王长陶；

【导师】 吴根茂；

【作者基本信息】 浙江大学 ， 机械电子控制工程， 2002， 博士

【摘要】 论文根据目前国内外材料试验机控制系统的现状，确立了“基于可拓控制策略的材料试验机电液比例控制系统的研究”这一研究课题，围绕材料试验机电液比例控制系统这一研究对象，进行了具有创新性、基础性、工程性及系统性的研究工作，获得了许多重要结论。 针对国内外材料试验机主要采用电液伺服控制系统，存在能耗大、温升、成本高、维护困难等问题，本课题提出了基于可拓控制策略的材料试验机电比例负载适应控制系统这一新型研究方案，通过开发新型试验机主机系统、液压缸系统、数字式微小流量电液比例流量阀及电控系统，实现了材料试验机电液比例负载适应控制，为我国材料试验机自动控制系统的产业化打下了基础。 针对国内材料试验机存在控制测量精度低、稳定性差，而国外试验机测量控制系统结构复杂、成本高、维护使用困难等问题，本课题研究开发了一种基于ISA总线的高性能、低成本的全数字式材料试验机测控系统，该测控系统的各项技术指标均达到并超过了国外先进同类产品的性能指标，对我国高性能材料试验机行业的发展具有重要意义。 针对试样刚度变化对负载刚度的影响问题，进行了负载刚度变化对控制系统影响的理论分析和仿真研究，从理论上分析了材料拉伸试样进入屈服阶段时试验过程产生震荡的原因，并研究开发了相应的可拓智能控制策略的解决办法，解决了国内外材料试验机工程界长期未解决的问题。 针对目前国内外材料试验机适用范围窄，各种控制方式不能灵活组合等问题，论文首次总结并提出了一套适合整个试验机行业的控制方式及约束推理条件，首次提出了一种新型CAPIES软件结构设计方法，实现了各种控制模式之间平滑、稳定切换，扩大了材料试验机的适用范围，为整个试验机行业的自动控制系统的设计提供了依据和参考。 本课题首次提出了一种基于图形库的测量器具动态特性求解新方法，该方法可以克服测量器具物理建模和数学建模时的相关误差，具有简便易行，准确度高，适用范围广等特点。可用于各种测量器具及各种控制系统的动态特性求解。 全文分八章。 第一章阐述了研究意义以及目前国内外材料试验机技术现状，介绍了材料试验机的基本组成及应用场合，分析了材料试验机的主要特点、典型控制方案和目前存在的问题。最后提出了作者的研究方案及方法。 第二章介绍了材料试验机负载适应控制系统的总体设计方案，详细介绍了本课题研究开发的主机系统、液压控制系统及电控系统。 第三章给出了材料试验机负载适应控制系统的数学模型，并针对不同的负载类型，对试验力控制系统、位置控制系统及变形控制系统进行了详细的理论分析及计算机仿真，并对理论分析和仿真结果作了讨论和总结。 第四章介绍了材料试验机CAPIES软件系统，详细介绍了CAPIES软件的组成原理和实现方法。 第五章介绍了可拓智能控制的原理，在此基础上，给出了材料试验机负载适应控制系统的可拓智能控制策略，实验证明，这种新型控制策略能够解决材料试验机结构参数变化问题，并能够实现各种控制模式之间的平滑切换。 第六章介绍了本课题的实验及结果，大量的实验证明，本课题的设计方案是完善而先进的，可拓控制策略的引入进一步提高了系统的控制性能及鲁棒性，CAP工ES软件系统的设计使得试验机能够适应各种不同的试验标准，大大提高了系统的适用性，具有较高的工程应用价值。 第七章提出了一种基于图形库的测量器具动态特性求解方法，该方法利用图象处理技术与识别技术首先将测量器具实验曲线与图形库中的标准曲线相比较，得到与实验曲线相匹配的标准特性函数，然后改变标准特性函数中参数，逐次迭代计算与实验曲线的相关函数，直至大于规定阂值，从而给出表示测量器具动态特性的算子表达式。该方法准确度高，适用范围广，适合于计算机自动求解各种不同系统的动态特性。 第八章对课题进行了总结和展望，给出了论文的研究成果，指出了进一步研究方向。更多还原

【Abstract】 Based on studies on current developments of the material testing machine control system, a new project about electro-hydraulic proportional control system for material testing machine based on extension control strategy is proposed. After a lot of creative projective basic and systematic study on control system of material testing machine, many important conclusions have been drawn.In order to solve the problems that large energy consumption, temperature variation, high, cost trouble maintenance in current electro-hydraulic servo control system for material testing machine, a new design scheme that electro-hydraulic proportional control system for material testing machine based on extension control strategy is proposed. The design scheme is successful by means of designing new main frame system, hydraulic cylinder system, digital electro-hydraulic micro-fluid proportional valve and electrical control system, and its results lay a foundation for material testing machine industries in our country.In order to solve the problems of low accuracy and stability in domestic material testing machine and complicate structure, high cost and trouble maintenance in foreign material testing machine, a high quality and low cost digital measure and control system for material testing machine based on ISA bus has been presented in this thesis and its performance indexes have been achieved and overachieved comparing with foreign advanced products, and it is important for the development of material testing machine industries in our country.As the variable stiffness of testing specimen affects load stiffness, the theoretical analysis and simulation study of the effect of variable load stiffness on the system are done. The degree and tendency of the effect of variable load stiffness on the control quality and accuracy are given, furthermore, a new extension control algorithm for material testing machine is presented in this thesis. By these algorithm, the problem existed and confused in testing machine engineering in a long term can be solved completely.In order to solve the problems of narrow application range and unwieldy control mode in current material testing machine, a set of control modes and constraint conditions fitting whole material testing machine industries have been proposed for the first time, furthermore, a new software CARIES, which shows new design method for material testing machine, has been developed, and it submits reference for the automatic control system design of material testing machine industries.A new method with high accuracy and wide application solving the dynamic characteristic of measurement system based on graph bank is proposed for the first time and it is suitable for automatic solving dynamic characteristic various system with computer.The thesis includes eight chapters.Chapter 1 is a survey. The current development of material testing machine is expounded. The basic component and application of material testing machine are introduced. Main characteristics and several typical design schemes of material testing machine are analyzed. In the last part of the chapter, the research method of the overall thesis is proposed.In chapter 2,the overall design scheme of electro-hydraulic proportional controlsystem of material testing machine is introduced. Main frame system, hydraulic control system and electronic controller design method are presented in detail.In chapter 3,the precious mathematics model about electro-hydraulic proportional control system of material testing machine is proposed. The digital simulation and theoretical analysis of load control system, position control system and extension control system are discussed according to various load type.In chapter 4, the CAPIES of material testing machine is introduced. The organization and realization method of CAPIES software system are presented in detail.In chapter 5, the design principle of extension control is introduced, and the extension control algorithm of electro-hydraulic proportional control sys更多还原