精密气动比例压力阀的关键技术研究

发布时间：2018-07-10 11:59

本文选题：比例压力阀 + 建模仿真　；参考：《浙江大学》2015年博士论文

【摘要】：近年来,国内气动技术发展迅速,在常规气动元件的研发方面取得了显著成绩,部分产品的质量和性能已达到世界先进水平,但在比例阀、伺服阀等高端气动元件的研发上则相对滞后,多停留在理论和实验室阶段,目前市场上尚未见到有性能良好的相关产品出现。气动比例压力阀因为具有动态特性好、控制精度高和易于电气集成等特点,在气动压力、速度、输出力和伺服定位等控制领域中获得了广泛的应用,遗憾的是现阶段气动比例压力阀的制造技术仅掌握在FESTO、SMC等少数国外大公司手中,国内使用的气动比例压力阀多依赖于进口。因此,开展气动比例压力阀所涉及的系列关键技术的研究,研发具有自主知识产权的比例压力阀产品,对实现我国气动比例控制元件自主化以及推动国内气动技术的发展具有重要的意义。本课题以一种调压范围在0～600 kPa的比例电磁铁驱动的直动式气动比例压力阀为对象,用理论-仿真-实验三者相结合的研究方法,系统的探讨了该阀的结构设计与数字比例控制器的设计方法。通过有限元和集总参数建模相结合的方法分析了系统的关键参数对阀的静、动态特性的影响以及系统的闭环控制特性。针对快速压力调节和高精度压力调节的不同需求,分别提出了新型鲁棒模糊PD控制算法(Novel Robust Fuzzy PD control, NRFPD)和自抗扰PI控制算法(Active Disturbance Reject PI control, ADRPI).最后将所设计比例压力阀应用于气缸轨迹跟踪控制的研究中,对样机的实际工作性能进行了试验验证。本文分为七个章节,现将各章内容分述如下：第一章,详细分析了气动比例控制技术的发展状况,指出了气动比例压力阀在比例控制技术中的重要地位；按不同的结构和应用场合分析了比例压力阀的研究现状；从数值仿真、比例控制器、控制策略以及具体应用等方面总结了与气动比例压力阀相关的研究进展；最后概括了本课题的研究意义及主要研究内容。第二章,详细分析了由比例电磁铁、活塞式阀芯、两位三通式阀体、反馈弹簧、压力传感器以及比例控制器等主要部件构成的比例压力阀样机的设计方法,阐述了负载对该阀输出性能的影响,指出了对其进行压力闭环控制的必要性。设计了比例压力阀的数字比例控制器,包含电源模块、信号调理模块、电流检测模块与驱动模块等,并利用改进的PID+anti-windup算法实现了电磁铁线圈电流的闭环控制。详述了气动比例压力阀的综合开发平台的设计,并利用该平台对样机进行了开环性能研究。第三章,首先建立了比例压力阀样机的从气源到负载的完整的非线性数学模型,采用了基于有限元-集总参数分析的混合模型对比例电磁铁动态性能进行建模,并分别对阀芯的运动特性与样机的气路结构进行了分析；其次通过仿真与实验结果的对比验证了模型的有效性；接着计算分析了关键气路结构参数对样机性能的影响；最后,利用PI控制器通过仿真研究了样机的闭环控制特性。第四章,针对输出压力的快速调整及在输出流量突变下的快速恢复,设计了一种新型鲁棒模糊PD控制器,主要由线性微分跟踪器(LTD)、模糊PD控制器和鲁棒控制项构成,其中LTD用于对反馈压力信号进行滤波和微分处理,模糊PD控制器用于实现对设定值的稳定跟踪,鲁棒控制项用于将压力控制的稳态误差减小到系统允许的误差范围内。数值仿真和实验结果表明NRFPD是有效的,具备良好的实际工作性能。第五章,首先分析了一种比例电磁铁直接驱动的截止式气动比例压力阀样机的输出压力控制器的设计难点；其次提出了基于电流环/压力环的双闭环控制的总体方案,电流环采用基于电流比例负反馈的模拟电路实现；为了实现对输出压力的高精度控制,压力环采用ADRPI控制算法,可分为两部分：当误差较大时,利用ADRC进行控制；当误差较小时,则切换至非线性PI控制器进行控制。同时,本文也引入了参考信号的规划来进一步改善压力输出的动态性能。最后通过大量的实验表明,所设计的控制器具有很高的输出压力控制精度,而且在下游负载变化时也能保证的压力控制的精度和稳定性。第六章,首先搭建了基于气动比例压力阀的阀控缸实验系统并分析了系统的组成原理；其次建立了系统的非线性状态空间模型；接着针对阀控缸实验系统系统中存在的参数变化和外界干扰等问题,提出了一种自适应鲁棒控制策略,利用带遗忘因子的在线最小二乘法来设计参数的自适应律,同时基于反步法设计了非线性鲁棒控制器,并结合期望运动轨迹初始化来改善系统的跟踪性能；最后通过实验对本文提出的自适应鲁棒控制器的性能进行了研究。第七章,对本论文的主要工作内容,研究结论和创新点进行了总结,并展望了未来的研究工作和研究方向。
[Abstract]:In recent years , the development of pneumatic proportional pressure valve has achieved remarkable achievements in the research and development of pneumatic proportional pressure valve . At last , the design proportional pressure valve is applied to the study of the track tracking control of the cylinder , and the actual working performance of the prototype is verified . The paper is divided into seven chapters , and the development of pneumatic proportional control technology is analyzed in detail , and the important position of the pneumatic proportional pressure valve in the proportional control technology is pointed out .
The research status of proportional pressure valve is analyzed according to different structure and application situation .
The research progress related to pneumatic proportional pressure valve is summarized from numerical simulation , proportional controller , control strategy and concrete application .
In chapter 2 , the design method of proportional pressure valve prototype composed of proportional electromagnet , piston valve core , two - position three - way valve body , feedback spring , pressure sensor and proportional controller is analyzed in detail .
Secondly , the validity of the model is verified by comparison between simulation and experimental results .
Then the influence of key gas path structural parameters on the performance of the prototype is analyzed .
Finally , the closed - loop control characteristics of the prototype are studied by using PI controller . In chapter 4 , a novel robust fuzzy PD controller is designed for fast adjustment of output pressure and rapid recovery under the abrupt change of output flow . The fuzzy PD controller is used to filter and differentiate the feedback pressure signal . The fuzzy PD controller is used to filter and differentiate the feedback pressure signal . The fuzzy PD controller is used to reduce the steady - state error of the pressure control to the allowable error range of the system .
Secondly , the general scheme of double closed loop control based on current loop / pressure loop is put forward , and the current loop is realized by analog circuit based on current proportional negative feedback ;
In order to control the output pressure with high accuracy , the ADRPI control algorithm can be used to control the pressure loop .
At the same time , the design of the reference signal is introduced to further improve the dynamic performance of the pressure output . At the same time , the paper also introduces the planning of the reference signal to further improve the dynamic performance of the pressure output . At last , a large number of experiments show that the designed controller has very high output pressure control accuracy and the accuracy and stability of the pressure control which can be ensured when the downstream load changes .
Secondly , the nonlinear state space model of the system is established .
In this paper , an adaptive robust control strategy is put forward aiming at the parameter change and external disturbance in the system of valve control cylinder , and the adaptive law of parameters is designed by the on - line least square method with forgetting factor , and the nonlinear robust controller is designed based on the backstepping method , and the tracking performance of the system is improved in combination with the expected motion track initialization .
At last , the performance of the adaptive robust controller proposed in this paper is studied experimentally . Chapter 7 summarizes the main work contents , research conclusion and innovation points of this thesis , and looks forward to the future research work and research direction .
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH138

【参考文献】