Fuzzy iterative learning control of electro-hydraulic servo system for SRM direct-drive volume control hydraulic press

A new kind of volume control hydraulic press that combines the advantages of both hydraulic and SRM(switched reluctance motor) driving technology is developed.Considering that the serious dead zone and time-variant nonlinearity exist in the volume control electro-hydraulic servo system,the ILC(iterative learning control) method is applied to tracking the displacement curve of the hydraulic press slider.In order to improve the convergence speed and precision of ILC,a fuzzy ILC algorithm that utilizes the fuzzy strategy to adaptively adjust the iterative learning gains is put forward.The simulation and experimental researches are carried out to investigate the convergence speed and precision of the fuzzy ILC for hydraulic press slider position tracking.The results show that the fuzzy ILC can raise the iterative learning speed enormously,and realize the tracking control of slider displacement curve with rapid response speed and high control precision.In experiment,the maximum tracking error 0.02 V is achieved through 12 iterations only.

Research and Development of Electro‑hydraulic Control Valves Oriented to Industry 4.0:A Review

Electro-hydraulic control valves are key hydraulic components for industrial applications and aerospace,which controls electro-hydraulic motion.With the development of automation,digital technology,and communication technology,electro-hydraulic control valves are becoming more digital,integrated,and intelligent in order to meet the requirements of Industry 4.0.This paper reviews the state of the art development for electro-hydraulic control valves and their related technologies.This review paper considers three aspects of state acquisition through sensors or indirect acquisition technologies,control strategies along with digital controllers and novel valves,and online maintenance through data interaction and fault diagnosis.The main features and development trends of electro-hydraulic control valves oriented to Industry 4.0 are discussed.

Research on characteristics of integrated type hydraulic transformer's control angle

In order to realize remote control of hydraulic transformers and improve the control precision of the pressure ratio,an integrated type electric hydraulic servo hydraulic transformer is proposed in this paper,a mathematical model is built and simulation of electro-hydraulic servo integrated hydraulic transformer's control angle is carried out,the principle prototype of the transformer is designed and manufactured,and experimental study is carried out on the experimental bench. The experimental results verify the correctness of the mathematical model. The results show that electro hydraulic servo control can improve the accuracy and dynamic response speed of control angle,which provides a reference for the further research of the hydraulic transformers.

Analysis and application in controlling surrounding rock of support reinforced roadway in gob-side entry with fully mechanized mining

In order to optimize gob-side entry in fully-mechanized working face in moderate-thick-coal seams, we adopt a new attempt to pack roadside by pumping ordinary concrete, which is very important for the development of gob-side entry technology. The concrete has a long initial setting time and a low initial strength. So it is difficult to control the surrounding rock. In this paper, we analyze the effect of using roadside cable to reinforce supporting in gob-side entry surrounding rock controlling based on elas-tic-plastic and material mechanics knowledge. And then we propose a scheme that cable is used to reinforce roadside supporting and a single hydraulic prop is used as the temporary supporting in gob side. Using the numerical simulation software FLAC2D, we numerically simulated supporting scheme. Results of both the 2D modeling and the industrial test on No.3117 face in Jingang Mine prove that the scheme is feasible. The results show that the technology of protecting the roadway in gob-entry retained efficiently make up the deficiency of roadside packing with ordinary concrete, effectively control the roof strata and acquire a good result of retaining roadway.

护盾式临时支护机器人带压行驶液压控制系统研究

护盾式临时支护机器人是适应夹矸与片帮共存的大断面巷道智能掘进机器人系统的重要组成部分,其主要功能是为实现“掘支并行”作业提供安全可靠的工作空间。为加强护盾式临时支护机器人推移行驶过程中对围岩的安全稳定支护,根据护盾式临时支护机器人结构、工作环境与作业需求,建立其带压行驶的推移量与支护力数学模型及带压行驶动力学模型,设计了护盾式临时支护机器人带压行驶液压控制系统。该系统主要由支护液压系统、行驶液压系统组成:静态支护时,支护液压系统需时刻输出大于上盾体自身重力的支护力,行驶液压系统处于待机状态;带压行驶时,支护液压系统和行驶液压系统同时工作,在保证临时支护机器人“减压不离顶”的同时,与顶板时刻带压并稳步前移。提出了基于模糊PID的护盾式临时支护机器人带压行驶精准控制方法:通过集成在推移油缸上的位移传感器与液压回路中的压力传感器实时采集临时支护机器人的压力与位移信号,用于反映临时支护机器人带压行驶途中支护力和行驶位移的变化情况,并根据支护力和推移量的误差和误差率,利用模糊PID算法对支护力和推移量的控制参数进行修正,实现基于模糊PID算法的带压行驶可靠控制。仿真与实验结果均表明,模糊PID控制的效果优于传统PID控制,在模糊PID控制下,护盾式临时支护机器人推移行驶过程中的支护力相对误差小于1%,行驶位移误差小于2 mm,且支护力和推移量控制响应速度快,保证了推移行驶过程中对围岩的安全稳定支护。

基于模糊神经网络PID的煤矿掘进机俯仰控制研究

目前煤矿掘进机俯仰控制主要采用PID控制方法,在掘进机俯仰控制时变性与液压系统非线性情况下的控制精度不高。掘进机俯仰控制通过控制液压缸行程实现,将传统PID算法与模糊控制、神经网络等相结合,可有效提高液压缸行程控制精度。提出了一种基于模糊神经网络PID的煤矿掘进机俯仰控制方法。通过分析掘进机支撑部运动学关系,得到俯仰角与支撑部液压缸的数学关系;介绍了掘进机俯仰控制液压系统工作原理,建立了液压系统及其传递函数模型;将模糊控制与神经网络相结合,形成模糊神经网络,利用模糊神经网络优化PID控制参数,再结合支撑机构数学模型和液压系统传递函数模型,建立掘进机俯仰角模糊神经网络PID控制模型,实现煤矿掘进机俯仰机构自动精确控制。该方法可使掘进机俯仰机构更加快速、准确到达预设位置,解决掘进机俯仰控制中的时变性与非线性难题。仿真结果表明:模糊神经网络PID控制算法相较于模糊PID和PID控制算法,跟踪误差分别降低了69.34%和74.49%。通过液压缸位移控制模拟煤矿掘进机在突变工况和跟随工况下的俯仰控制,结果表明:模糊神经网络PID控制算法相比模糊PID和PID控制算法,俯仰控制跟踪误差最小,对位置信号的平均响应时间分别缩短了27.22%和50.33%,动态控制性能更好。

A practical nonlinear robust control approach of electro-hydraulic load simulator

This paper studies a nonlinear robust control algorithm of the electro-hydraulic load simulator （EHLS）. The tracking performance of the EHLS is mainly limited by the actuator＇s motion disturbance, flow nonlinearity, and friction, etc. The developed controller is developed based on the nonlinear motion loading model. The problems of the actuator＇s disturbance and flow nonlinearity are considered. To address the friction problem, the friction model of the loading motor is identified experimentally. The friction disturbance is compensated using the obtained friction model. Therefore, this paper considers the main three factors comprehensively. The developed algorithm is easy to apply since the controller can be obtained just with one step back-stepping design. The stability of the developed algorithm is proven via Lyapunov analysis. Both co-simulation and experiments are performed to verify the effectiveness of this method.

A method to perform prognostics in electro-hydraulic machines: the case of an independent metering controlled hydraulic crane

Remaining useful life (RUL) estimation is a topic that has gained more and more attention in the field of fluid power systems, thanks to the tremendous potentials shown for improving safety and reduced production losses. However, many challenges related to RUL estimation are not solved yet, mainly connected to the definition of the health status of each component. A prognostic method based on a data-driven methodology for hydraulic systems is here proposed to estimate the percentage of life already spent by the monitored components. The potentials of the methodology are shown considering the case of a truck-mounted hydraulic crane, for which a simulation model was available.

深地煤炭资源安全高效智能化开采关键技术与实践

深地煤炭资源地质赋存复杂,智能化开采是深地资源安全、高效、绿色发展的必由之路。智能化开采成套技术与装备能否适应千米深井复杂地质环境、控制围岩稳定并驱动装备跟随煤层自动推进是影响煤炭安全高效开采、减少作业人员、降低劳动强度的关键。山东能源集团聚焦千米深井智能化开采围岩控制理论,提出了以强度耦合、刚度耦合和稳定性耦合为核心的支架-围岩智能耦合关系,并形成与之相适应的智能耦合控制逻辑;为突破超大采高智能综采开采工艺及超高煤壁围岩控制技术瓶颈,提出了超大采高液压支架工作阻力“双因素控制法”,发明了三滚筒采煤机及其配套开采方法,研制了与超大采高智能综采相匹配的液压支架及配套系统;针对超大采高综放开采智能化放煤理论与围岩控制难题,提出超大采高综放支架-围岩耦合协调采放空间控制方法,创新了超大采高综放“马鞍形”开采工艺,研制了7 m超大采高智能综放开采液压支架及配套系统;研发了无反复支撑、快速循环自移的单元式超前支架,解决了回采巷道超前支护距离长、支护技术与装备适应性差的问题;开发了基于惯导和精准地质模型的智能采煤控制系统,解决了深部矿井工作面设备智能控制及困扰连续生产的难题;搭建了千米深井智能化开采综合管控平台,实现了千米深井重大灾害多源异构数据融合与管控。上述核心技术在山东能源集团赵楼煤矿7302工作面、东滩煤矿3308工作面等多个工作面进行了智能化开采示范建设,取得了良好的应用效果,所获成果整体推动了我国深地煤炭资源安全高效智能化开采水平,可以为类似矿井智能化工作面建设提供理论与技术借鉴。

基于变形控制的某深埋软岩水工隧洞初期支护参数的选择与验证

大变形下围岩的稳定控制一直是水利水电、公路、铁路等行业的传统难题,尚未形成一套验证软岩大变形等级下初期支护型式及参数选取的经验方法。依据某深埋水工隧洞工程地质情况,选择典型洞段预测挤压变形风险,利用控制变形估算所需支护力,依据规范和相关工程经验确定支护类型与参数的同时,考虑实际开挖过程利用数值仿真分析验算支护的合理性。结果表明,该隧洞具有极大的大变形风险,采用支护力的方法所确定的支护类型和参数基本合理,可将围岩变形有效控制在规范要求的1.0%~3.0%范围,且锚杆长度及支护应力等均未超过极限强度。

煤矿智能化液压支架控制系统研究

煤矿智能化开采是煤炭行业未来发展的重要方向。智能化开采的关键技术之一是智能化液压支架控制,其主要作用是实现煤矿井下集控、地面远控,保障煤矿自动化生产。重点分析了智能化液压支架控制系统的配置,主要包括液压支架电液控制系统、工作面视频监控系统、工作面人员定位系统、工作面自动找直系统、工作面智能化集中控制系统等。可以为煤矿智能化提供一定的技术参考。

液压支架电液控制系统故障诊断系统设计研究

针对以往液压支架电液控制系统采用人工排查故障存在随机及个别故障无法准确定位、故障排查效率低下等问题,设计一种基于大数据的新型液压支架电液控制系统故障诊断系统,建设大数据决策分析服务平台,设计基于MapReduce的C4.5决策树分类故障诊断预测引擎,对硬件设备进行技术改造升级。研究结果表明,该故障诊断系统能对电液控制系统的各类故障进行有效识别和诊断,实践应用效果显著。

顺槽大采高超前液压支架液压控制系统设计与仿真分析

为满足顺槽大采高超前液压支架的自动化控制的需求,本文结合顺槽支护时超前液压支架的电控及手动控制需求,围绕这两方面需求针对性设计对应控制回路,然后依次构建了各回路的仿真分析模型,再运用AMESim液压仿真软件展开仿真分析,结合仿真结果分析各回路的位移变化情况并针对性调整回路,仿真结果证实,液压控制系统设计方案能够实现煤矿顺槽的自动支护,可以保证煤炭开采过程的安全。

液压支架液控系统的动态特性分析

为提升液压支架液压系统工作效率,应用AMESim仿真软件分析支架立柱液控系统动态特性,表明增大泵站流量可明显提升升柱速度,对降柱速度影响小;缩短伸缩杠位移,可缩短升降柱时间;增大液控单向阀直径、供液管路直径,可提升升降柱速度,并在液控系统最优参数组合下,升柱时间为3.5 s,提升约17%;立柱降柱时间为2.1 s,提升约16%,提升液压支架立柱控制系统效率.

中等稳定以下顶板条件顺槽超前支护支架的研制

针对大采高综采工作面中等稳定顶板条件的运输顺槽顶板超前支护的问题,研制了大工作阻力的运输巷超前支护液压支架,解决了中等稳定以下顶板条件运输顺槽超前机械化支护问题,介绍了用于神东矿区的ZYDC11000/30/47型运输巷超前支护支架的总体结构、主要技术参数、电液控制系统、支架在巷道中的布置工艺以及使用情况。

液压支架电液控制系统的故障诊断研究

在煤矿井下开采过程中,因为受到恶劣环境等因素干扰,液压支架电液控制系统经常发生故障,需要不断对其进行检修维护,做好故障诊断工作,才可以提高电液控制系统的稳定性。对液压支架电液控制系统的组成及运行原理进行研究,基于电液控制系统的故障因素,对故障快速排除技术及大数据决策分析服务平台进行了具体分析,并对液压支架的实际运行效果展开了讨论,借助有效的故障诊断,及时发现问题并进行处理,以期提高液压支架的稳定性。

煤矿井下液压支架组智能控制系统的应用研究

煤矿作业中液压支架故障频发,主要是因为液压支架控制系统的协调性差、调控精度低、自主调节能力不足,增大了采矿作业风险。为解决这一问题,以液压支架组智能控制系统为研究对象,分析了液压支架支护机理,提出了智能化液压支架支护系统设计原理,指出了系统功能与结构设计要点,分析了应用效果,但缺乏案例与数据支撑,未来需从这一方面加以改进,保障研究深度。

关于矿用液压支架自动控制系统的设计与应用分析

以ZC8800/20/38型固体充填液压支架为研究对象,结合实际情况设计了自动控制系统。该系统中设置有支架控制器,作用是对传感器数据进行收集,同时对液压支架进行控制。各支架控制器之间及其与井下主机之间利用RS485总线进行数据交互。井下主机利用交换机与地面主控计算机进行连接。支架控制器型号为S7-200型PLC控制器。软件程序方面,重点介绍了落料自动控制、推压密实机构控制过程。自动控制系统经过地面调试、井下工业试验和工业应用,发现整体运行稳定,达到了预期效果,安全效益和经济效益显著。

液压支架立柱外缸筒开裂的防治策略

以A煤矿液压支架立柱外缸开裂问题为例,介绍一种外缸筒开裂的防治策略。该方法先要对液压支柱外缸开裂问题的基本情况与原因进行分析,然后以此为基础,通过激光熔覆再造技术对开裂区域予以修复,以此提升外缸质量的良好性。通过该防治策略的应用,可显著提高外缸筒的强度,有利于液压支架更好地使用,确认该防治策略具有一定应用价值。

矿用液压支架自动化控制的优化分析

在煤矿井下开采中,液压支架作为综采工作面重要的支护设备,其支护效果直接影响到矿井开采的安全性。在煤矿开采智能化、自动化水平不断提高的情形下,需要做好液压支架的自动化控制工作,降低人工移架的强度,提高巷道支护的安全性。为此,从提高支架自动化控制精度出发,基于支架自动化控制的概述,应用BP(Back Propagation,逆向传播)神经网络算法构建支架姿态自动化预测控制系统,对支架的姿态进行准确的预测,进而提高液压支架的自动化控制精度。最后,经过技术试用,证实姿态自动化控制系统能提高支架的自动化控制水平。