Tri-state Modulation Power Driving of Electro-hydraulic Proportional Amplifier

Switch electro-hydraulic proportional amplifier（PA） widely employs single switch modulation power driving（SSMPD） or reverse discharging power driving（RDPD） at present. SSMPD has slow dynamic response, and can＇t adjust independently the dither signal＇s amplitude and frequency; RDPD accelerates the current decay; consequently, it increases current ripple and power loss. For the purpose of solving the above mentioned problem, the tri-state modulation power driving（TSMPD） scheme was proposed for improving the performance of power driving. Detailedly, the hardware circuit for the tri-state modulation power driving is designed; the tri-state modulation algorithm is realized by digital signal processor（DSP）. The tri-state modulation power driving is investigated by experiments, comparetive experiments among the single switch modulation power driving（SSMPD）, reverse discharging power driving（RDPD）, and the TSMPD are implemented, and the experimental results demonstrate that the linearity error of TSMDP meets the requirement of PA; the current response of TSMSP is the best; the amplitude of ripple current of the TSMPD can be reduced without increasing frequency of PWM, in addition, dither signal amplitude and frequency can be adjusted independently for each other. It is very meaningful to guide the development of high performance proportional amplifier for high frequency response proportional solenoid.

Investigation of Semi-Active Hydro-Pneumatic Suspension for a Heavy Vehicle Based on Electro-Hydraulic Proportional Valve

Hydro-pneumatic suspension is widely used in heavy vehicles due to its nonlinear characteristics of stiffness and damping. However, the conventional passive hydro-pneumatic suspension can’t adjust parameters according to the complicated road environment of heavy vehicles to fulfill the requirements of the vehicle ride comfort. In this paper, a semi-active hydro-pneumatic suspension system based on the electro-hydraulic proportional valve control is proposed, and fuzzy control is used as the control strategy to adjust the?damping force of the semi-active hydro-pneumatic suspension. A 1/4?semi-active hydro-pneumatic suspension model is established, which is co-simulated with AMESim and MATLAB/Simulink. The co-simulation results show that the semi-active hydro-pneumatic suspension system can significantly reduce vibration of the vehicle body, and improve the suspension performance comparing with passive hydro-pneumatic suspension.

RESEARCH ON THE PERFORMANCE OF NEW TYPE OF PROPORTIONAL PESSURE AND FLOW CONTROL VALVE

A new closed loop flow controlling principle through correcting the valve'sopening area while load pressure is changing is carried out. Further more a principle using only oneproportional valve to compound control pressure and flow is suggested. By using very simpleproportional throttle valve in structure, the functions that five kinds of proportional valves orany two of them combined possess can be complimented. After analyzing, comparing, and testing thedynamic and static characteristics of valve with different controlling principles and main valvestructure styles, the optimized structure styles and control methods are achieved.

Research on Electro Hydraulic Proportional Control for Heavy Vehicle Blend Braking System

A blend braking system of heavy vehicle was proposed.The main control part of the system is the electro hydraulic proportional servo valve.A nonlinear model of brake cylinder controlled by the valve was deduced through the analysis of its control property and system feature.The transfer function of the system was also proposed,and the hydraulic inherent frequency and the PID closed-loop system feature were calculated.The simulated result is consistent with those tested in the bench and on the site with 50 t heavy vehicle.The experimental result shows that the control method has quick response and high precision.

ROBUST CONTROL OF AN ELECTROHYDRAULIC PROPORTIONAL SPEED CONTROL SYSTEM WITH A SINGLEROD HYDRAULIC ACTUATOR

A robust control algorithm is proposed to focus on the non-linearity and parameters＇ uncertainties of an electro-hydraulic proportional speed control system （EHPSCS） with a single-rod hydraulic actuator. The robust controller proposed does not need to design stable compensator in advance, is simple in design and has large scope of uncertainty applications. The feedback gains of the robust controller proposed are small, so it is easily implemented in engineering applications. Experimental research on the speed control under the different conditions is carried out for an EHPSCS. Experimental results show that the robust controller proposed has better robustness subject to parametric uncertainties, and adaptability of parameters＇ variation of control system itself and plant parameter variation.

农业机械电液控制技术发展现状及展望

电液控制技术作为农业机械关键技术之一,对于增强机械性能、提升操作便捷性和提高生产效率具有显著影响。综述了农业机械电液控制技术发展现状,通过具体案例,展示先进电液控制元件及系统在提升农业机械整体性能,特别是在模块化订制、智能化控制、电驱高效节能等方面的作用和潜力。未来以人工智能和物联网为代表的先进技术将与电液控制系统相结合,进一步推动农业机械向智能化和无人化方向发展。

高比例新能源电网AGC技术研究

为实现区域电网负荷与发电的平衡,确保连续性供电,自动发电控制技术(AGC)近年来得到迅猛发展。基于高比例新能源电网AGC技术应用现状,总结AGC相关控制目标及策略,并结合某域电网实际运行情况,归纳联络线调节、常规断面混合调节与新能源断面调节的控制策略,为AGC技术领域的未来研究提供参考依据。

一种新型最速控制技术:原理和应用

在实际的控制工程领域中,传统的比例–积分–微分(PID)控制仍然占主导地位.一阶惯性滤波器(FOIF)是构建PID结构的基础.加速型工程最速比例–积分(AEFPI)控制器则是以加速型工程最速跟踪滤波器(AEFTF)为基础构造的,然而,对于AEFPI的全面研究和分析还缺乏.本文提出了FOIF原型的问题,并通过研究和分析最速跟踪滤波器机理与物理缺陷、工程化重构加速型工程最速滤波器输出跟踪输入特性、频域滤波特性以及所构造的AEFPI控制器的控制性能等方面,从技术角度揭示了低通滤波器属性对所构造控制器性能具有决定作用.通过数学计算分析、仿真实验验证以及现有工程实践结合,说明了这种AEFPI控制器具备显著反馈控制性能.

锈红色清水混凝土的质量控制及施工技术研究

以杭钢旧址公园工程为研究背景,从原材料选择、配合比设计、模板工程、施工工艺等方面探讨了锈红色清水混凝土的质量控制及关键施工技术,为推动彩色清水混凝土施工技术的发展提供了有益借鉴和指导。

基于电液比例技术的采煤机调高控制的优化设计及模拟

针对采煤机滚筒调高采用定量泵-换向阀,存在调节精确度、性能低等,优化设计采用电液比例采煤机调高液压系统,首先仿真分析开闭环PID调高控制,其能够实现滚筒轨迹的精确跟踪,且闭环PID控制特性明显优于开环控制;并在上述闭环PID调高控制基础上,仿真分析扰负载、过负载影响,结果表明:该调高系统可实现对干扰负载的忽略、过负载滚筒高度的自动调节。

SMT回流焊工艺分析及其温控技术的实现

随着电子器件微型化及表面贴装技术(Surface Mounted Technology,SMT)的发展,热风回流焊机在电子制造业中的应用日益广泛。然而,在回流焊过程中,由于被控参数的非线性、不确定性等因素,传统的比例-积分-微分(Proportion Integral Differential,PID)控制器难以取得满意的控制效果。针对SMT回流焊工艺的特点,分析温控技术在回流焊过程中的重要性,并探讨温控技术的实现方法。设计一整套多中央处理器(Central Processing Unit,CPU)嵌入式硬件系统,并使用改进PID控制算法控制热风回流焊机。针对回流焊机温区多、人工参数整定效率低的问题,研究PID参数自整定的方法。在改进PID控制算法的基础上,提出上位机插值模糊PID控制算法。所提出的温控技术能够有效提升回流焊质量,满足现代电子制造业的高精度要求。

C100高强大体积混凝土配合比设计及施工温控技术

随着混凝土向高性能、高强度方向发展,C100高强大体积混凝土已经逐渐应用于超高层建筑、大跨度桥梁等重点工程领域,而在地下工程中使用C100高强大体积混凝土较少,相关的施工技术研究有限。本文以某地下工程综合应用C100高强大体积混凝土为研究对象,从工程施工环境着手,重点研究C100高强大体积混凝土配合比设计及施工温控技术。从配合比设计入手,通过数值模拟计算分析C100高强大体积混凝土温度场变化情况,采取施工工艺优化、内部冷却水降温、跳仓浇筑、表面保温隔热、冬季施工控制、智能测温及养护等温度控制技术。结果表明:在满足高强度指标前提下,该技术基本解决了大断面高强大体积混凝土施工中的水化热温升控制以及水化热温升引起的温度裂缝问题,达到了设计要求,确保了工程施工质量。

基于人工智能的火电厂锅炉燃烧系统故障预测与诊断

火力发电厂锅炉系统的可靠性和效率直接影响整个发电系统的性能和稳定性,因此提出一种基于人工智能的火电厂锅炉燃烧系统故障预测与诊断方法,结合自适应控制的智能冷却系统和数字孪生技术,实现对锅炉温度的精确控制和故障预测。智能冷却系统通过比例-积分-微分(Proportional Integral Derivative,PID)控制算法动态调节冷却介质的流量,保持锅炉在最佳温度范围内运行。利用数字孪生技术构建锅炉系统的虚拟模型,与实际系统实时同步,进行状态监测和故障预测。结果表明,该系统能够快速响应温度变化,保持系统稳定,有效预防故障的发生,提高了锅炉系统的运行效率和可靠性。

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.

某大型装备电液比例实验台的控制系统设计

针对某大型装备电液比例系统的控制复杂、性能难掌握等特点,设计一种基于大型装备的电液比例实验台控制系统。对电液比例实验台的组成和功能进行介绍,对PLC可编程控制系统、电气控制系统和HMI人机交互系统进行设计,并对实验台的控制系统进行试验。试验结果表明:该控制系统能实现对系统元器件技术指标和参量的检测分析,可对控制系统参数和性能的曲线变化情况进行监测。

一种高比例户用光伏智能减载控制方法

随着户用光伏在配电网中的占比日益提升,原有低压减载方案已经体现出一定的不适用性。为解决高密度户用光伏并网后的低压减载问题,提出了基于多智能体技术的高密度户用光伏智能减载控制方法。首先,分析了光伏的有功-无功调压原理。然后,基于多智能体技术提出智能减载单元分层协同控制策略;最终,利用改进粒子群算法实现智能减载控制。仿真结果表明,所提的方法能在一定程度上实现智能减载,减小电压偏移,具有一定的可靠性和实用性。

一种六轴含独立增压缸的七轴联动多向热模锻液压机

介绍一种七轴联动多向热模锻液压机。其具有六轴均含独立增压缸的独特结构。通过对本案例液压系统的理论计算和对比分析显示,在多轴联动的大型液压设备领域,基于蓄能器和增压缸的节能型高节拍液压机控制技术与传统液压控制技术相比,在节能降耗方面具有非常明显的优势。与直供式伺服电机控制系统相比,尽管受到补能容积占比偏低的不利影响,仍能在众多工况条件下在省电方面不落下风(基本持平,略有超越),并在节省耗油量、节省电机装机容量和节省企业基本电费方面呈现明显优势。

多路换向阀的发展历程与研究展望

多路换向阀是工程机械液压系统中的关键部件之一。综述了多路换向阀的发展历程,分析了其发展背景及存在的关键问题。着重分析了最新的抗流量饱和技术、负流量控制技术和带电液负载敏感的负载口独立控制电液比例多路阀。展望了该领域今后的研究方向。

挤压机机电控制系统研究

本文探讨了12.5MN轻合金挤压机的机电系统控制问题,对应用电液比例技术、伺服控制技术、模/数、数/模转换器及可编程控制器实现等温挤压的具体方法作了深入细致的研究,文中所述方法对挤压机的机电系统控制具有一定的普遍意义。

自动变速器比例电磁阀优化设计与分析

以自动变速器用比例电磁阀为研究对象,研究了比例电磁阀关键参数的设计及其优化方法。在结构分析的基础上,分析了其工作原理,将比例电磁阀分为电磁、机械和流体三部分。建立了比例电磁阀阀芯动力学方程,分析了影响电磁阀动态响应时间及油压动态输出的因素。对比例电磁阀的电磁铁部分进行了优化设计,确定了电磁力和输入电流之间的关系后;采用遗传算法的优化方式,以比例电磁阀阀芯质量、弹簧刚度、弹簧的预压缩量和阻尼系数为优化设计参数,比例电磁阀油压输出的响应时间及超调量为优化目标,对比例电磁阀进行优化设计与分析;设计中通过改变遗传算法的种群范围、遗传代数、交叉率及变异率,得到了多种比例电磁阀的结构方案,并进行了部分试验验证。研究结果表明:通过优化方法可以得出比例电磁阀的优化设计参数,优化后的比例电阀输出油压动态响应时间提高了12.5%,油压超调降低了50%,能够满足自动变速器电液换挡控制系统综合要求。