基于粒子群神经网络液压泵效率特性仿真分析

为了能够实现对液压泵效率特性的多点计算,深入地研究了粒子群神经网络在液压泵效率特性分析中的应用。首先,分析了液压泵效率特性的基本原理;其次,研究了RBF神经网络的基本原理;然后,剖析了改进粒子群的优化算法;最后,进行了液压泵效率特性试验测试和仿真分析结果比较,比较结果表明粒子群神经网络在进行液压泵效率特性计算时具有较高的计算精度和计算效率。     

液压泵效率与排量特性试验研究

为实现工程机械液压系统的高效节能,对液压泵的效率和控制特性进行试验研究.基于液压试验台,测试了液压泵在不同压力、转速和排量下的效率,并进行了建模分析.之后对液压泵排量的动态与静态电比例控制特性进行了对比试验.研究结果表明液压泵的高效区分布于等值线图的右上角,即中高转速和排量范围内.液压泵排量控制特性基本不受转速影响,受负载压力影响较大,新旧液压泵的排量控制特性基本相同.研究为工程机械动力匹配奠定了基础.     

液压泵总效率的热力学测试方法

随着液压技术在工业上的广泛应用,液压系统的可靠性日益成为用户关注的问题。从使用寿命及节能角度来看,液压泵的效率值是一个重要指标,而其监测手段的改进是人们感兴趣的课题。过去,在对系统诊断时,往往凭经验判断泵的磨损和泄漏程度,或采用系统解体后把泵送到试验台进行容积效率、机械效率的测试,这就需要对多项参数(压力,流量、转矩、转速、功率)进行测量和分析计算。在此,采用一种较简便的热力学方法来获取液压泵的总效率。本方法的基本原理早在1914年法国人Poirson用温差法测定水轮机效     

温度对液压泵主要性能参数的影响

建立了液压泵一些性能参数和温度的关系的简化数学模型，绘制出其特性曲线，再与试验曲线相比较，说明温度对液压泵的实际流量、容积效率、输出功率等的影响不容忽视。因此，只有同时研究液压泵的压力特性和温度特性，才能较全面地评价一个泵的性能。     

基于负载效率的异步电机工作区间研究

从液压泵的无因次效率特性曲线入手,结合液压泵本身的转速范围及功率曲线得出轴向柱塞定量泵的工作点区间。再根据异步电机与液压泵的功率匹配特性推导出异步电机的工作区间,进而划分出异步电机的三个特殊工作点:怠速工作点、正常工作点和超载工作点。最后通过在Simulink搭建的基于直接转矩控制的异步电机控制系统仿真模型对异步电机的三个特殊工作点进行仿真,仿真结果表明:异步电机在直接转矩控制系统控制下能够准确快速到达这三个工作点并平稳运行。     

液压泵、液压马达容积效率检测方法的研究

利用流体的压缩性和热膨胀理论建立了液压泵加载阀上游与加载阀下游输出流量之间关系的数学关系式,建立了液压马达输入流量与输出流量和外泄漏量之间的数学关系式。指出在液压泵试验中采用现行检测方法（即测量加载阀下游流量的方法）测得的容积效率总是大于其真实值、测得的总效率也偏高,建议采用测量加载阀上游流量的方法;指出在液压马达试验中采用现行检测方法（即测量马达输出流量和外泄漏量的方法）测得的容积效率总是小于其真实值,测得的总效率也偏低,建议采用测量液压马达输入流量的方法。     

基于模糊神经网络的汽车液压泵的故障诊断研究

为了达到准确地对汽车液压泵进行故障诊断的目的,深入地研究了模糊神经网络在故障诊断中的应用.首先,分析了模糊RBF神经网络模型以及对应的算法流程;接着,根据汽车液压泵所存在的故障建立了故障诊断的数据样本对模糊神经网络进行训练;最后,利用训练后的模糊神经网络对汽车液压泵进行故障诊断,结果表明,模糊神经网络具有非常高的故障诊断效率.     

液压泵微机测控系统的试验与研究

本文通过实验,研究了液压泵试验台的微机测控系统,利用此系统可对液压泵的压力、流量、转矩、转速等参数进行静态与动态测试,通过计算机采集信号和数据处理,可直接由计算机打印出泵的流量、效率、功率特征曲线和相关参数的计算结果.     

基于人工神经网络的液压泵工作特性建模

为了确定液压泵的高效率工作区域,需要做出其工作特性图,传统的作法需要大量的测试数据.本文给出了一种采用人工神经网络建模的方法,运用三层BP网络,只需要少量数据就可以建立液压泵的工作特性模型,输出液压泵的各种工作特性值.     

汽车起重机电液流量匹配系统非线性特性研究

针对汽车起重机变转速电液流量匹配系统液压泵流量非线性和非线性负载扰动问题,提出了一种基于先验数据的液压泵流量非线性映射模型。首先,搭建了电机、定量泵和液压缸的数学模型;其次,通过实验测得了液压泵压力、转速与容积效率的关系,拟合出了容积效率云图,构建了泵的流量非线性映射模型;最后,以变幅机构为分析对象,利用AMESim软件搭建了系统仿真模型,进行了液压泵的流量非线性和非线性负载扰动在流量补偿前后的对比仿真分析。研究结果表明：在液压泵流量非线性映射模型的补偿作用下,系统能够对电机转速进行补偿,使液压泵的输出流量不随负载压力的变化而变化,当负载出现25 kN、50 kN和75 kN阶跃波动时,最大流量波动幅值分别减小52.1%、47.9%和43.5%,验证了所提出的流量非线性模型的有效性,提升了变幅伸缩机构的控制精度和运动平稳性。     

NOISE IDENTIFICATION FOR HYDRAULIC AXIAL PISTON PUMP BASED ON ARTIFICIAL NEURAL NETWORKS

The noise identification model of the neural networks is established for the 63SCY14-1B hydraulic axial piston pump. Taking four kinds of different port plates as instances, the noise identification is successfully carried out for hydraulic axial piston pump based on experiments with the MATLAB and the toolbox of neural networks. The operating pressure, the flow rate of hydraulic axial piston pump, the temperature of hydraulic oil, and bulk modulus of hydraulic oil are the main parameters having influences on the noise of hydraulic axial piston pump. These four parameters are used as inputs of neural networks, and experimental data of the noise are used as outputs of neural networks. Error of noise identification is less than 1% after the neural networks have been trained. The results show that the noise identification of hydraulic axial piston pump is feasible and reliable by using artificial neural networks. The method of noise identification with neural networks is also creative one of noise theoretical research for hydraulic axial piston pump.     

基于Kriging模型的液压柱塞泵可靠性灵敏度分析

液压柱塞泵作为液压系统的核心动力元件,其能量转换效率很大程度上决定了整个液压系统的性能和可靠性,而目前采用的能量转换效率模型多为确定性数值模型,没有考虑参数随机性的影响,无法真实反映柱塞泵的实际运行状态。提出了基于Kriging模型的柱塞泵总效率建模方法,选用柱塞泵总效率为可靠性失效判据,分别采用改进一次二阶矩法和Monte-Carlo数值仿真法对柱塞泵总效率进行可靠性和可靠性灵敏度分析。分析结果表明:Kriging模型采用少量的样本模拟的总效率模型具有较高的精度,模拟结果可以获取全面的柱塞泵效率特性;运行工况条件对柱塞泵总效率可靠性灵敏度具有重大影响,不同工况下灵敏度具有较大差异。提出的方法可推广至其他液压泵总效率模型的建立及可靠性灵敏度分析。     

基于小波包分解和RBF神经网络的民机液压泵源故障诊断研究

液压泵源是民机液压系统的动力部分,对于民航飞机飞行的安全起着重要的作用。由于民机液压泵结构复杂,故障机理繁多,因此其故障诊断难以用常规方法实现。提出了基于小波包分解和RBF神经网络的民机液压泵源故障诊断方法。采集民机液压泵轴向和径向的振动信号,利用小波包分解将振动信号进行分解,得到的各频带信号的能量作为神经网络的输入。经过RBF神经网络的计算以实现民机液压泵源的故障诊断。     

双流道泵输送固液介质的水力性能及磨损试验研究

为分析固液混合物对双流道输送泵性能的影响,采用平均粒径为10 mm和36 mm的固体颗粒对双流道泵在不同浓度和流量下开展输送固液两相介质的水力性能试验,并对泵的磨损进行分析。水力试验结果表明,在一定的流量下,随着输送混合物中固体颗粒浓度的增加,入口表压、出口表压、扬程及效率呈递减趋势。 与输送清水时比较,当输送固液两相介质时,随着流量的增大,轴功率上升较快,扬程的下降量在不同流量下几乎相同;效率曲线在不同流量下比输送清水时效率要低,差值随着流量的增大而增大。在同流量同浓度比工况下,泵的进出口压力、扬程和汽蚀性能在输送较大直径固体颗粒时,明显下降。通过对双流道泵磨损的分析表明,叶轮磨损部位主要在前盖板外缘、流道内偏前盖板的流道表面、压力面进口边,压力面的磨损区域呈三角形;泵体的磨损部位主要在周壁、隔舌及泵体口环处。本研究可为固液两相双流道离心泵的理论研究与设计应用提供试验依据。     

APPLICATION OF ARCHITECTURE- BASED NEURAL NETWORKS IN MODELING AND PARAMETER OPTIMIZATION OF HYDRAULIC BUMPER

The dynamic working process of 52SFZ-140-207B type of hydraulic bumper is analyzed. The modeling method using architecture-based neural networks is introduced. Using this modeling method, the dynamic model of the hydraulic bumper is established; Based on this model the structural parameters of the hydraulic bumper are optimized with Genetic algorithm. The result shows that the performance of the dynamic model is close to that of the hydraulic bumper, and the dynamic performance of the hydraulic bumper is improved through parameter optimization.     

液压系统用齿轮泵压力不足发热冒烟故障分析

通过对某液压产品中所使用的齿轮泵的故障问题的分析,提出解决的办法,并且总结了在同类型的产品中遇到类似问题的处理意见以及在液压齿轮的装配中应该注意的事项,以提高液压系统的使用效率和使用寿命。     

Output characteristics of a series three-port axial piston pump

Driving a hydraulic cylinder directly by a closed-loop hydraulic pump is currently a key research area in the field of electro-hydraulic control technology,and it is the most direct means to improve the energy efficiency of an electro-hydraulic control system.So far,this technology has been well applied to the pump-controlled symmetric hydraulic cylinder.However,for the differential cylinder that is widely used in hydraulic technology,satisfactory results have not yet been achieved,due to the asymmetric flow constraint.Therefore,based on the principle of the asymmetric valve controlled asymmetric cylinder in valve controlled cylinder technology,an innovative idea for an asymmetric pump controlled asymmetric cylinder is put forward to address this problem.The scheme proposes to transform the oil suction window of the existing axial piston pump into two series windows.When in use,one window is connected to the rod chamber of the hydraulic cylinder and the other is linked with a low-pressure oil tank.This allows the differential cylinders to be directly controlled by changing the displacement or rotation speed of the pumps.Compared with the loop principle of offsetting the area difference of the differential cylinder through hydraulic valve using existing technology,this method may simplify the circuits and increase the energy efficiency of the system.With the software SimulationX,a hydraulic pump simulation model is set up,which examines the movement characteristics of an individual piston and the compressibility of oil,as well as the flow distribution area as it changes with the rotation angle.The pump structure parameters,especially the size of the unloading groove of the valve plate,are determined through digital simulation.All of the components of the series arranged three distribution-window axial piston pump are designed,based on the simulation analysis of the flow pulse characteristics of the pump,and then the prototype pump is made.The basic characteristics,such as the pressure,flow and noise of the pumps under different rotation speeds,are measured on the test bench.The test results verify the correctness of the principle.The proposed research lays a theoretical foundation for the further development of a new pump-controlled cylinder system.     

全飞行剖面下的航空液压泵热载荷分析与温度预测

基于理论分析和仿真实验,研究了影响航空液压泵温度变化的因素.首先,对航空液压泵的基本情况进行了简述,通过数学建模建立了航空液压泵的效率模型,对泵的功率损失进行了详细分析;然后,利用控制体方法建立了描述泵的各部分温度变化的热力学模型,通过理论计算分析了泵在不同工况下的温度变化;在此基础上,利用MATLAB对航空液压泵在飞...     

Performance study based on inner flow field numerical simulation of magnetic drive pumps with different rotate speeds

Magnetic drive pump has gotten great achievement and has been widely used in some special fields.Currently,the researches on magnetic drive pump have focused on hydraulic design,bearing,axial force in China,and a new magnetic drive pump with low flow and high head have been developed overseas.However,low efficiency and large size are the common disadvantages for the magnetic drive pump.In order to study the performance of high-speed magnetic drive pump,FLUENT was used to simulate the inner flow field of magnetic drive pumps with different rotate speeds,and get velocity and pressure distributions of inner flow field.According to analysis the changes of velocity and pressure to ensure the stable operation of pump and avoid cavitation.Based on the analysis of velocity and pressure,this paper presents the pump efficiency of magnetic drive pumps with different rotated speeds by calculating the power loss in impeller and volute,hydraulic loss,volumetric loss,mechanical loss and discussing the different reasons of power loss between the magnetic drive pumps with different rotated speeds.In addition,the magnetic drive pumps were tested in a closed testing system.Pressure sensors were set in inlet and outlet of magnetic drive pumps to get the pressure and the head,while the pump efficiency could be got by calculating the power loss between the input power and the outlet power.The results of simulation and test were similar,which shows that the method of simulation is feasible.The proposed research provides the instruction to design high-speed magnetic drive pump.     

大型水泵出水流道优化水力设计

研究大型水泵出水流道扩散角、断面形状和中心线走向对水力损失的影响,提出当量扩散角概念,以包括沿程摩阻水力损失、扩散水力损失和出口水力损失在内的总水力损失最小为目标,对出水流道扩散角和断面形状进行优化,提出流道中心线走向优化的原则。研究结果表明,在进、出口断面位置一定的情况下,出水流道存在最优扩散角,使总水力损失最小。试验证明,由于水泵出水弯管的作用,出水流道实际开始脱流的扩散角小于理论计算的最优扩散角;采用优化渐变扩散角,可使水力损失进一步减小;矩形流道断面以正方形为最优,且存在最优角圆,使单位长流道沿程水力损失最小。成果对减小出水流道水力损失,实现泵装置优化设计,提高泵装置效率有重大意义。