伺服力矩马达输出转矩影响因素分析

电液伺服阀作为液压伺服控制元件中的核心元件,能将微弱信号转换为大功率信号,力矩马达作为电液伺服阀的核心元件,其性能直接影响电液伺服阀的性能。为了分析力矩马达输出转矩的影响因素,基于AMESim搭建仿真平台对各个因素进行分析,结果表明,永磁体剩余磁化强度、衔铁中心到衔铁末段距离、气隙处磁极面积和线圈匝数对力矩马达输出转矩影响较大,永磁体的长度以及横截面积和衔铁处于中位时气隙长度对力矩马达输出转矩影响较小,并通过试验验证了其正确性。     

Novel torque motor model for performance design and analysis of a servo valve with permanent magnets

Servo valves are widely used for modern hydraulic actuator control. This valve consists of a torque motor with permanent magnets. In present study, a novel torque motor model is derived by considering magnetic flux leakage and demagnetization effect of the permanent magnets involved in the servo valve. The derived model was validated by comparing experimental data with the model calculation represented with physical parameters. Since these two important physical phenomena, missing in the previously well-known model, are considered in the newly derived torque motor model, it can be used for the physical parameter design of a torque motor and the analysis of a servo valve controlling electro-hydraulic servo systems.

     

浅析液压锁电磁场对电液伺服阀组件的影响

首先对电液伺服阀组件工作原理进行了介绍,然后在对电液伺服阀和液压锁的电磁场进行分析的基础上,探索了组合条件下液压锁的电磁场对电液伺服阀输出性能的影响。分析表明,液压锁电磁场产生磁通的大小和方向与液压锁的实际工作电压及供电极性相关,电液伺服阀力矩马达工作气隙处的原有磁通叠加后会改变衔铁的偏转力矩,最终导致伺服阀组件的输出压力变化。最后,通过改变液压锁供电电压和供电极性,进行了试验验证。     

双阀控制在电液负载仿真台中的应用

根据压力伺服阀和流量伺服阀在电液负载仿真台中的应用特点，提出一种由压力伺服阀和流量伺服阀组成的双阀控制加载方案。对比结构不变性原理补偿方法可知，此双阀控制方法在克服多余力矩及提高性能指标方面更有效。     

一种新型力矩马达的建模研究

为了更好地控制电-气阀门定位器,根据力矩马达的动作原理,采用机理分析的方法,分析了新型力矩马达的输出力矩与磁通的关系和输入电压与磁通的关系;在此基础上分别建立了该新型力矩马达的磁路模型和电路模型;最后,建立了力矩马达可动铁片的转角与输入电压之间的传递函数。通过实验图和仿真图的对比,实验验证了模型的正确性。     

双喷嘴挡板伺服阀弹簧管刚度对伺服系统的影响分析

对双喷嘴挡板伺服阀进行全面建模,分别从力矩马达、衔铁挡板组件、滑阀3个部件进行数学建模。力矩马达数学建模考虑了永磁体漏磁、导磁元件磁阻、永磁体磁阻及工作气隙因素;衔铁挡板组件模型考虑了其平动和转动两个自由度;而滑阀的数学建模采用常规建模方式。同时引入其他模型与所建立的模型通过AMESim仿真进行对比分析,并且逐步分析了弹簧管刚度对位置伺服系统和变幅伺服系统的影响。     

基于转矩控制的定排量恒压电液动力源运行特性

通过协调电液动力源转速和排量可以提升其能效,也是目前电液动力源的研究热点,随着变频和伺服技术的发展,变转速电液动力源也越来越多地应用在工业生产和航空航天装备中。目前,电液动力源实现流量控制可以采用变排量控制,也可以采用变转速控制,这两种控制方式已非常成熟,应用也较多。但在压力控制中,还往往只能依赖液压泵变排量控制结合压力反馈实现压力控制机能,采用变转速控制压力时,难以适应负载流量随机快速变化工况。为此,提出采用高效率的伺服电动机直接驱动定量泵,进一步提出基于转矩控制和转速补偿的压力控制方案,在负载压力变化时,无需控制电动机转速,具有动态响应快、系统结构简单的优点。通过理论分析和试验研究,结果表明,采用设计的方案可以很好地实现压力控制,在相同条件下,与常规恒压变量泵相比,压力响应时间从160 ms降低到50 ms,响应速度远超国际同类恒压控制泵。     

舵机被动式加载系统多余力矩分析

分析舵机被动式加载系统的工作原理以及多余力矩的产生机理,研究液压动力元件的结构及电液伺服阀与多余力矩的关系,进一步分析多余力矩的本质特征,探讨抑制多余力矩的有效方法.     

基于伺服电流与切削力关系的间接测量技术研究

分析了切削加工过程,依据三相永磁同步交流伺服电机矢量控制原理,提出伺服电流间接监测切削力的测量方法,并提取了反映切削力变化的电机电流信号特征参数.基于转矩模拟平台、霍尔元件,设计并搭建电磁转矩-进给伺服电流实验平台,进行伺服电流与转矩关系测量实验,研究实时监测进给伺服驱动单元的电流信号.     

电液伺服舵机加载系统设计与研究

分析了电液伺服舵机加载系统中多余力控制、电液伺服阀的工作原理、控制系统设计等多项舵机加载系统中的关键技术,并在此基础上阐述了电液伺服舵机加载系统的组成部分和设计过程。     

射流管伺服阀AMESim建模与仿真

对二级力反馈射流管电液流量伺服阀的结构及工作原理进行了分析研究,利用AMESim中的基本库及元件库进行力矩马达磁路、滑阀组件的建模,利用AMESet工具进行衔铁组件及射流放大器的建模,建立射流管流量伺服阀的整阀AMESim模型,仿真结果与实际情况吻合。     

New method to improve dynamic stiffness of electro-hydraulic servo systems

Most current researches working on improving stiffness focus on the application of control theories.But controller in closed-loop hydraulic control system takes effect only after the controlled position is deviated,so the control action is lagged.Thus dynamic performance against force disturbance and dynamic load stiffness can’t be improved evidently by advanced control algorithms.In this paper,the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil is analyzed.On this basis,the conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put forward.And a scheme using double servo valves to realize flow feedforward compensation is presented,in which another fast response servo valve is added to the regular electro hydraulic servo system and specially utilized to compensate the compressed oil volume caused by load impact in time.The two valves are arranged in parallel to control the cylinder jointly.Furthermore,the model of flow compensation is derived,by which the product of the amplitude and width of the valve’s pulse command signal can be calculated.And determination rules of the amplitude and width of pulse signal are concluded by analysis and simulations.Using the proposed scheme,simulations and experiments at different positions with different force changes are conducted.The simulation and experimental results show that the system dynamic performance against load force impact is largely improved with decreased maximal dynamic position deviation and shortened settling time.That is,system dynamic load stiffness is evidently raised.This paper proposes a new method which can effectively improve the dynamic stiffness of electro-hydraulic servo systems.     

阀用超磁致伸缩致动器双排串联式弓张结构设计与研究

在所设计超磁致伸缩致动器输出性能基本不变的条件下,为增大其输出位移以满足大流量电液伺服阀的驱动需求,设计了一种双排串联式弓张结构;基于材料力学知识建立了双排串联式弓张结构输出位移模型,并分析了其结构尺寸参数对其放大比的影响;采用有限元仿真的方法分析了双排串联式弓张结构输入力与输出位移之间的关系;制作了双排串联式弓张结构样机,搭建试验系统对其放大性能进行了测试。试验结果表明：双排串联式弓张结构的放大倍数在16.5～16.9之间波动,与理论计算值基本吻合,所设计双排串联式弓张结构能够满足大流量电液伺服阀的驱动要求。     

Development of a novel two-dimensional(2D) three-way(3W) fuel flow control servo valve with constant pressure difference

To solve the problems of large volume, and low integration of traditional electro-hydraulic servo valve with constant pressure differential fuel metering device, a new two-dimensional three-way constant pressure differential fuel flow control servo valve (2D3WFFCSV) is developed. It innovatively adopts the advantages of lightweight of “two-dimensional hydraulic technology”, The constant differential pressure function and flow regulation function are integrated into a two-dimensional (2D) main spool with two degrees of freedom (rotational and axial degrees of freedom). The flow control process of 2D3WFFCSV is as follows: firstly, the armature of the torque motor and the two-dimensional piston are coaxially installed at the end of the two-dimensional piston, so the torque motor can directly drive the two-dimensional piston to rotate; secondly the “hydraulic servo screw mechanism”, which can amplify the power, is used to drive the two-dimensional piston to move in line; Finally, a pair of conversion mechanisms (roller group and spiral track conversion mechanism) are converted into the angular displacement of 2D main spool to control the area of flow valve port. The axial degree of freedom of 2D main spool realizes the function of constant differential pressure. To improve the flow control accuracy of the servo valve, the axial position of the 2D piston is detected by the linear displacement sensor (LVDT), and the signal is transmitted to the controller to realize the closed-loop control. To explore its open-loop characteristics, the mathematical models of torque motor, two-dimensional piston and main spool are established to obtain its open-loop transfer function. Then the AMESIM simulation model is built. To optimize the design of the system, through the dynamic simulation of the system, the influence of key parameters on the dynamic response of the system can be studied. An experimental study is carried out to verify the design feasibility of the servo valve. The experimental results show that under the condition of no-load and full-scale input, the closed-loop delay of the servo valve is 1.84%, the linearity is 2.14%, the step response time is 43 ms, and the dynamic frequency response is 38 Hz. The newly developed 2D3WFFCSV has the advantages of high integration, small size, light weight (801.5 g) and high response and control accuracy. It can replace the constant differential pressure, metering valve and hydraulic servo valve in the aeroengine fuel regulator.     

混合定子铁心再制造电机应变数值仿真与转矩不平衡分析

提出将永磁电机的机壳、端盖、转子等零部件留用,定子铁心更换为由非晶合金叠片和硅钢叠片轴向混合叠压而成的混合定子铁心的永磁电机再制造方式。以一台混合定子铁心再制造电机为对象,分析了电机的空载气隙磁密轴向分布规律;计算了非晶合金定子和硅钢定子对应的径向力密度,应用电磁机械耦合模型对再制造电机应变进行数值分析;研究了再制造电机单位电磁转矩轴向分布规律,给出了再制造电机电磁转矩计算公式,发现了非晶合金定子和硅钢定子对应电磁转矩不相等引起的转矩不平衡现象,分析了转矩不平衡对转子铁心的影响。制作了再制造电机并进行了振动试验,试验结果证明了分析的正确性。     

气动电磁阀开启过程的动态响应特性

以二位三通气动电磁阀为研究对象,详细介绍了其工作机理并对磁路进行理论分析。通过ANSYS Maxwell软件建立其二维电磁场分析有限元模型,并进行瞬态运动仿真计算,分析多电磁参数(主气隙宽度、铁磁材料、动铁芯直径、弹簧预紧力、刚度以及线圈加载方式)对电磁阀瞬态响应特性的影响。搭建实验平台,测试线圈加载方式对电磁阀瞬态响应特性的影响,进一步验证了仿真分析的准确性。为类似电磁类产品的设计研发提供了充实的理论依据。     

数字式阀门电动装置力矩辨识研究

提出一种新型阀门电动装置力矩辨识方法。从异步电动机的数学模型入手,推导了静止两相直角坐标系下力矩与电压、电流关系表达式,进而实现了只须检测电动机的电压和电流即可辨识出阀门电动装置的瞬时力矩,而无须安装机械检测装置。仿真和实验结果证明了该方法的正确性和实用性,其精度完全能够满足工业生产的需要。该项研究为智能型阀门电动装置转矩机构设计提供了理论依据。     

电液伺服阀动态特性数据处理方法的研究

电液伺服阀动态测试过程中,由动态缸高频振动引起的测试台架振动、现场存在变频器等设备造成的电磁干扰以及传感器电源波动等因素,均会以速度测试通道噪声的形式窜入数据采样通道,这些噪声信号幅值强弱不同且频宽很广,采用硬件滤波手段难以有效消除,导致电液伺服阀的频率特性测量数据信噪比降低,如果不进行有效的数据滤波处理,会导致对电液伺服阀动态性能评价失效。针对这一问题,提出了采用FIR和IIR滤波器双联滤波的方法,并对含有上述噪声信号的数据进行了理论分析和实验研究,结果表明,该方法有效的消除了非线性干扰,提高了电液伺服阀动态特性的测量精度。     

Halbach阵列磁弹簧减压阀特性研究

为改善传统减压阀中机械弹簧应力松弛和疲劳断裂等问题,提出一种基于Halbach阵列磁弹簧的直动式减压阀。利用Maxwell对Halbach阵列磁弹簧进行磁力仿真,设计出满足减压阀性能要求且铁磁耗材较低的Halbach阵列。利用AMESim软件仿真分析静态压力-流量特性与动态阶跃响应特性对Halbach阵列磁弹簧减压阀与机械弹簧直动式减压阀的影响规律。结果表明：相较于同规格机械弹簧直动式减压阀,Halbach阵列磁弹簧减压阀压力-流量曲线更平缓,即入口流量相同的情况下,磁弹簧减压阀压力损失更小,稳压精度更高;当进出口压差为2.5 MPa时,响应速度接近,当进出口压差提升至4.5 MPa时,Halbach阵列磁弹簧减压阀压力脉冲较小,即超调量较小,响应速度略有提高。     

2D阀控电液激振器的优化设计和实验研究

为了进一步提高电液激振器的激振频率和控制精度,并降低其加工和安装难度,提出了2D高频激振阀的新结构和控制方法。通过增加2D阀阀芯沟槽与阀套窗口的沟通次数,改进与无刷直流伺服电机连接的高速齿轮箱传动机构,设计混合式直线步进电机与堵头连接以控制阀芯轴向位移,实现了对2D高频激振阀的结构优化。经理论以及实验研究表明：新型2D高频激振阀的结构简单,控制精度高,激振频率最高可达3000Hz。