大吨位液压机多模式电液控制系统关键技术研究

发布时间：2018-01-02 00:16

  本文关键词：大吨位液压机多模式电液控制系统关键技术研究　出处：《浙江大学》2017年博士论文　论文类型：学位论文

  更多相关文章： 大吨位液压机 多模式电液控制系统 单反馈比例插装阀 数学建模 实验平台 模糊PID控制 扩展的分段干扰观测器 扩展的模糊干扰观测器 非线性层叠控制器 最小等效负载准则 滑模控制 backstepping 最优能量分配-自适应鲁棒

【摘要】：液压机,特别是大吨位的液压机,有必要具备多种工作模式,以满足不同类型产品的生产需求。电液控制系统作为液压机的核心组成部分,其工作性能不仅决定了液压机的工作特性,而且显著影响到被压制产品的质量;因此,希望液压机具备多种工作模式,首先必须要求液压机的电液控制系统具备多种工作模式并存的能力。然而,以往的研究中很少有学者针对液压机的电液控制系统,特别是大吨位液压机的多模式电液控制系统展开深入的研究。本论文将以某大型锻造液压机为研究背景,以大吨位液压机的多模式电液控制系统为具体的研究对象,从核心元件、外负载补偿策略、非线性控制策略等方面出发,对大吨位液压机多模式电液控制系统的关键技术进行系统的研究。本论文共六章,每一章的摘要如下:第一章,概述了液压机的特点及分类、国内外研究现状以及未来的发展趋势,并指出多模式并存是未来大吨位液压机设计中必然考虑的一个问题,继而详细介绍了与大吨位液压机多模式电液控制系统相关的四大关键技术,即电液比例插装阀技术、液压机的外负载建模技术、基于干扰观测器的外负载补偿技术以及电液控制系统的控制技术,并指出了现有技术应用于多模式电液控制系统所存在的问题;最后,阐述了本课题的来源及研究意义,介绍了本论文的研究内容。第二章,针对某一款单反馈比例插装阀(single-feedback proportional cartridge valve, SFPCV)展开系统的研究。首先介绍了 SFPCV的工作原理,然后根据相关的性能指标对SFPCV的主要零部件进行设计,并建立了 SFPCV的非线性数学模型;根据SFPCV的非线性数学模型,建立了 SFPCV的MATLAB/AMESim联合仿真模型,并通过仿真数据与样机实验的对比验证了所建联合仿真模型的正确性;依托所建联合仿真模型,进一步研究了相关结构参数对SFPCV工作性能的影响规律,从而为SFPCV的改进提供依据;根据仿真结果并结合实验,对SFPCV的主要结构参数及控制策略进行了改进。实验结果表明:所研发SFPCV的相关动静态性能达到了设计指标,可以替代进口,应用于大吨位液压机的多模式电液控制系统中去。第三章,首先介绍了某大型锻造液压机多模式电液控制系统的工作原理,针对其与其他类型液压机所共有的、用以完成一般产品压制成形的低速工进系统以及其所特有的蓄能器辅助快锻系统,搭建了相应的实验平台。为了便于后续基于数学模型的非线性控制器设计,建立了实验平台的数学模型,并通过开环仿真及实验的对比验证了所建数学模型的正确性。考虑到后续的研究中需要用到实验平台中的加载液压缸对驱动液压缸进行模拟加载,还进一步研究了加载液压缸的加载控制算法。实验结果表明:采用模糊PID控制算法能够在保证静态加载精度与传统PID控制算法相仿的前提下,显著改善加载的动态过程。第四章,针对未知载荷作用下的低速工进系统高性能运动控制展开系统的研究。首先提出了两种不同的干扰观测器对液压机在低速工进阶段所受到的外负载进行在线估计和补偿:第一种干扰观测器基于外负载可分段线性化这一特点而提出,它的参数自适应由观测器误差和运动跟踪误差同时驱动,本文中把它称为“扩展的分段干扰观测器 ”(extended piecewise disturbance observer, EPDO);第二种干扰观测器基于模糊系统可以以任意精度逼近未知非线性系统这一特点而提出,它的参数自适应同样由观测器误差和运动跟踪误差同时驱动,本文中把它称为“扩展的模糊干扰观测器 ”(extended fuzzy di sturbance observer, EFDO)。针对电液控制系统固有的强非线性特性以及各种模型不确定性,并且考虑到负载口独立控制的低速工进系统的多输入-单输出特性,提出了 一种非线性层叠控制器作为低速工进系统的运动控制器:该非线性层叠控制器的位移跟踪环基于滑模控制而设计,以期望的位移、速度、加速度以及加加速作为输入,以期望的驱动力作为输出;该非线性层叠控制器的压力跟踪环基于backstepping技术而设计,使系统的实际驱动力能够精确跟踪位移跟踪环得出的期望驱动力。针对负载口独立控制的低速工进系统的静态工作点选择问题,提出了一种适用于液压机的“最小等效负载准则” (minimum equivalent load criterion,MELC):该准则把驱动缸有杆腔(相当于液压机的回程缸)提供的力看作等效外负载的一部分,随着估计外负载的增大逐渐减小驱动缸有杆腔的期望压力,并保证最小的等效外负载大于滑块的重力;从而能够最大限度地挖掘出液压机的驱动能力,并且保证液压机在任何状态下都不会出现失稳现象。仿真和实验结果表明:采用本文所提出的非线性层叠控制器,并结合本文所提出的EPDO或EFDO,能够使得液压机在低速工进过程中精确跟踪给定的期望位移曲线;在EPDO或EFDO的作用下,估计的外负载能够在观测器误差和运动跟踪误差的驱动下精确跟踪低速工进过程中所受到的实际外负载;此外,在本文所提出MELC的作用下,控制器能够根据估计外负载的大小,自动改变驱动缸有杆腔的期望压力,从而可以尽可能地挖掘出液压机的驱动能力,提高其位移跟踪性能。第五章,针对蓄能器辅助快锻系统的高频次、高精度、平稳位移控制展开系统的研究。首先从蓄能器辅助快锻系统的基本结构出发,进行核心元件的参数匹配设计。继而在考虑蓄能器辅助快锻系统的多输入-单输出特性,以及蓄能器辅助快锻系统所受到的各种匹配或者不匹配模型不确定性的基础上,提出了 一种最优能量分配-自适应鲁棒控制(optimal energy distributed adaptive robust control,OED-ARC)策略作为蓄能器辅助快锻系统的运动控制器:在OED-ARC控制器的设计中首先把“集总流量”看作系统的等效输入,使得系统的输入输出自由度相等;然后根据期望的运动轨迹,利用backstepping技术推导出“集总流量”的期望值;最终再根据“最优能量分配准则”从“集总流量”推导出两个控制阀的实际控制量。此外,在OED-ARC控制器的设计中还采用了 一种基于蓄能器简化数学模型的“非线性阻尼调节器”来对蓄能器数学模型中存在的非线性参数不确定性进行补偿。仿真和实验结果表明:采用本文所提出的OED-ARC控制器可以使蓄能器辅助快锻系统获得确定的动态特性和静态跟踪精度,即使系统中存在各种匹配或者不匹配的模型不确定性;此外,采用本文所提出的“非线性阻尼调节器”不仅可以较好地补偿蓄能器的非线性参数不确定性,还可以起到微调运动控制效果的作用,增加了系统的调节自由度。第六章,总结了本论文的研究工作;阐述了本论文的主要创新点;并对后续的研究工作进行了展望。
[Abstract]:Hydraulic machine, especially large tonnage hydraulic machine, it is necessary to have a variety of operating modes, different types of products to meet the production demand. The electro-hydraulic control system of hydraulic machine as the core part, its performance not only determines the working characteristics of hydraulic machine, and significantly affect the quality of products is suppressed; therefore, I hope the hydraulic machine with various working modes, we must first request of the electro-hydraulic control system of hydraulic machine capable of coexistence of multiple modes of operation. However, scholars of the electro-hydraulic control system for hydraulic machine with few previous studies, especially deeply studies of large tonnage hydraulic machine multi mode electro-hydraulic control system in this paper. With a large forging hydraulic press as the research background, with the large tonnage hydraulic machine multi mode electro-hydraulic control system as the research object, from the core element, the external load compensation strategy, nonlinear control Strategy aspects of systematic research on the key technology of large tonnage hydraulic machine model of electro-hydraulic control system. This thesis consists of six chapters, each chapter summary is as follows: the first chapter summarizes the characteristics and classification of hydraulic machine, research the status quo and future development trend, and points out the multi mode there is a problem in the future design of large tonnage hydraulic machine must be considered, and then introduces the related large tonnage hydraulic machine model of electro-hydraulic control system of four key technologies, namely, the electro-hydraulic proportional cartridge valve technology, modeling technology of hydraulic load, load control technology and electro-hydraulic control compensation technology the system based on disturbance observer, and pointed out that the existing technology is applied to the model of the electro-hydraulic control system of the existing problems; finally, expounds the origin and significance of the research, introduces the research content. The two chapter, aiming at a single feedback proportional cartridge valve (single-feedback proportional cartridge valve, SFPCV) system research. First introduces the work principle of SFPCV, then designed according to the main components of performance indicators related to SFPCV, and the nonlinear mathematical model of SFPCV is established; based on the nonlinear mathematical model of SFPCV. The establishment of a joint simulation of MATLAB/AMESim SFPCV model, and the correctness of the United simulation model is verified by comparing the simulation data and the experimental; relying on the United simulation model, further study the structure parameters influence on the working performance of SFPCV, which provides a basis for SFPCV according to the simulation results and improvement; according to the experiment, the main structure parameters of the SFPCV and the control strategy is improved. The experimental results show that the dynamic and static performance related to development of SFPCV The design index, can replace the imported used in large tonnage hydraulic machine model of electro-hydraulic control system. The third chapter, firstly introduces the working principle of a large forging hydraulic machine model of electro-hydraulic control system, the hydraulic machine and other types of common, low speed feeding system to complete the general the product forming and its unique accumulator fast foging system, build the experimental platform. In order to facilitate the subsequent design of nonlinear controller based on the mathematical model, established the mathematical model of the experimental platform, the correctness and through comparison of open-loop simulation and experimental verification of the mathematical model is considered. To follow-up studies need to use the hydraulic cylinder of the experimental platform for driving the hydraulic cylinder to simulate loading, a further study of the hydraulic cylinder load control algorithm. The experimental results show that using fuzzy PID control algorithm can guarantee the static loading precision with traditional PID control algorithm under the premise of similar dynamic process, significantly improve the load. In the fourth chapter, according to the movement of the unknown load low speed feeding system of high performance control system research. The paper puts forward two different disturbance observer is used to estimate and compensate the online the hydraulic machine is in low speed feeding stage load: the first external load disturbance observer can be piecewise linearization based on this characteristic, it consists of parameter adaptive observer error and tracking error while driving, this paper called it "subsection extended interference observer (extended piecewise disturbance observer. EPDO); second kinds of disturbance observer fuzzy system can approximate the unknown nonlinear system is proposed based on the characteristics of it, the same adaptive parameters Sample by the observer error and tracking error driven at the same time, this paper called it "fuzzy disturbance observer extended" (Extended Fuzzy di sturbance observer, EFDO). For strong nonlinear characteristics of hydraulic control system and various inherent model uncertainty, and taking into account the smismo low speed feeding system of multi input single output characteristics, this paper presents a nonlinear cascade controller as low-speed motion controller work into the system: the design of sliding mode control based on tracking loop displacement of the nonlinear cascade controller, with the desired displacement, velocity, acceleration and acceleration as input and output as the driving force to the desired tracking technology is designed based on the backstepping; the nonlinear controller of the pressure ring stack, the system can accurately track the actual driving force displacement tracking the desired driving force. For the ring Choose smismo speed feeding system static working point, a method is presented for the hydraulic machine "minimum equivalent load standards" (minimum equivalent load criterion, MELC): the standard drive cylinder cavity (the return cylinder equivalent hydraulic machine) part of the force provided as equivalent with the increase of the load, the load estimation decreases gradually drive cylinder cavity of the desired pressure, and ensure minimum equivalent load is larger than the slider gravity; so as to maximize the driving capability of hydraulic machine, hydraulic machine and ensure that in any state there are no instability phenomenon. The simulation and experiment the results show that the nonlinear cascade controller is presented in this paper, combined with the EPDO or EFDO, expected displacement curve can make accurate tracking of the given hydraulic machine at low speed in the process of feeding; In EPDO or EFDO, the estimated load drive of the observer error and tracking error of tracking real low speed feeding is in the process of load; in addition, the role of MELC in this paper, the controller can estimate according to the load size, automatically change the cylinder cavity the expected pressure driven, which can dig out the driving ability of hydraulic machine, improve the displacement tracking performance. In the fifth chapter, aiming at the high frequency, accumulator fast foging system with high precision, steady displacement control system research. First, from the basic structure of accumulator fast foging system of match the design parameters for core components. Then considering the multi input accumulator fast foging system - single output characteristics, and the energy storage device of fast foging system by the match or do not match the model uncertainty On the basis of the proposed control an optimal allocation of energy - (optimal energy distributed adaptive adaptive robust robust control, OED-ARC) strategy as the motion controller accumulator fast foging system: in the design of the OED-ARC controller in the lumped equivalent input flow as a system, the input and output of equal degree of freedom system according to the desired trajectory; then, using backstepping derived "lumped flow" expectations; finally according to the "energy allocation criteria" optimal "set from the actual control of the total flow derived two control valves. In addition, the OED-ARC controller is adopted in the design of a storage based on it is a simplified mathematical model of the nonlinear damping regulator of accumulator mathematical model in nonlinear parameter uncertainty compensation. The results of simulation and experiment table The OED-ARC controller is used in this paper can be fast foging system to obtain the dynamic characteristics and static tracking precision to determine the energy storage system, even if there are various match or do not match the model uncertainty; in addition, the proposed nonlinear damping controller not only can effectively compensate the nonlinear parameter storage it is uncertain, but also to fine tune the motion control effect, increase the degree of freedom adjustment. The sixth chapter summarizes the research work of this paper; expounds the main innovation points of this paper; and the subsequent research work is prospected.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TH137;TP273
，

本文编号：1366847