液压系统多缸同步控制技术研究

针对液压多缸同步控制技术进行研究,建立了液压多缸同步系统的控制模型。使用等状态交叉耦合控制策略对液压多缸同步系统进行控制;使用模糊PID算法代替常规PID算法作为液压多缸同步控制系统的核心算法。仿真研究的结果表明,使用模糊PID算法相比常规PID算法,能够有效提高液压多缸同步控制系统的跟踪性能和同步控制性能。     

基于T-CPU的多缸电液比例同步控制系统研究与应用

介绍了多缸同步控制的几种传统方法,国内外多缸电液比例同步控制技术的发展概况.论述了基于西门子T-CPU(Technological tasks with SIMATIC)进行多缸电液比例同步控制系统的技术方案,包括硬件组成原理、软件系统、“同步轴”概念等,并介绍了其在液压板料折弯机中的应用.     

双马达模糊神经网络速度同步控制实现方法研究

针对内嵌式溢油回收机扫油臂与卷筒双马达电液驱动速度同步控制问题,对扫油臂和卷筒驱动系统的组成、工作原理和控制要求进行了阐述;基于"等同控制"策略,引入模糊神经网络控制理论,建立了双马达模糊神经网络控制器;运用Matlab软件对模糊神经网络控制系统与PID控制系统进行了仿真,获得了阶跃响应对比曲线和线速度同步误差对比曲线,探讨了速度同步控制系统的稳定性,分析了线速度同步误差特点与形成原因。研究结果表明:模糊神经网络控制系统几乎无超调、调节时间为5.2 s,PID控制系统超调量为23%、调节时间为8 s,速度达到稳定时,模糊神经网络控制系统线速度差为7 mm/s,PID控制系统线速度差为16 mm/s;与PID控制相比,模糊神经网络控制具有更好的动态响应特性和稳态特性,同步误差更小、同步精度更高。     

推床同步控制系统研究及其应用

该文先对电液位置同步控制系统进行了结构分析,然后根据结构分析的结果设计了推床位置同步控制系统,并对其进行了PID控制,实验证明满足了推床液压系统的同步控制精度要求。     

电液多轴控制系统中偏差积分式自跟随同步的算法与实现

该文介绍电液多轴控制系统的主从位置同步控制算法及其原理,分析该算法在液压系统中的仿真结果和实际系统的跟踪曲线。结果表明:偏差积分式自跟随同步的算法具有同步控制精度高、抗干扰能力强、在多轴控制器上易于实现的优点。     

基于AMESim/Simulink的轮式两栖车静压行驶驱动系统马达同步控制联合仿真研究

分析了液压同步控制回路形式,重点研究了电液比例阀控同步回路,以电液比例阀控四马达同步液压系统为研究对象,建立了同步系统液压和控制模型,利用AMESim/Simulink对四马达同步系统进行了基于模糊PID控制的联合仿真分析,结果表明,电液比例阀控四马达同步液压系统,响应速度快,同步精度高。仿真为这种新型同步控制方式的可行性验证以及进一步的发展与研究提供了依据与理论支持。     

液压挖掘机神经网络控制的研究

电液比例控制系统具有多变量、强耦合、非线性的特点.采用常规的PID控制时,系统的控制性能对模型的误差比较敏感,在系统工况变化较大(如长行程、变负荷等工况)时,系统的总体控制精度不高,不能满足工作装置的控制要求.神经网络控制器具有的强非线性拟合特性为解决此类问题提供了一条有效的途径.该文以液压挖掘机的电液比例控制系统为对象,利用仿真试验手段对神经网络控制器应用于电液控制系统时的设计及参数调整方法进行深入的研究,以期利用神经网络控制器提高在高时变强非线性系统时获得良好的全局控制性能.该文首先介绍了液压挖掘机大臂液压比例控制系统的组成及控制要求,基于此电液比例控制系统的特点并结合神经网络控制理论基础,对神经网络控制器的设计方法进行探讨,在仿真过程中通过观察控制器参数对系统响应性能的影响作用对其进行调整,并利用其结果与PID控制器的控制效果进行比较以验证设计方法的正确性及控制器的自适应性与鲁棒性.     

液压拉床双缸IPSO-PID伺服同步驱动控制研究

针对单缸驱动液压拉床存在刀架溜板同步性能较低的问题,设计了双缸电液伺服同步驱动系统,在分析刀架溜板拉削运动特性的基础上建立了系统的非线性模型;根据系统跟踪性能和同步性能指标要求,引入改进型粒子群优化算法(IPSO),提出了类似经典PID控制器结构的IPSO-PID伺服同步控制策略。在液压拉床上的实际应用结果表明,该控制策略比常规PID同步控制策略具有更好的跟踪性能和同步驱动性能,可以较好地解决双缸液压拉床的同步驱动问题。     

1000 t惯性摩擦焊液压多缸同步控制策略研究

针对大吨位惯性摩擦焊机多缸液压顶锻系统强干扰、强非线性的特点,面向多缸系统同步性能的高精度、强抗干扰的要求,基于自行设计的一套具有位置反馈的三缸液压顶锻系统,建立了阀控缸系统以及位置反馈同步系统的动态响应数学模型,并且提出了以伺服阀控液压系统为基础,在偏差耦合控制方式下采用模糊PID对控制参数进行优化的多缸同步控制策略。在MATLAB Simulink中对该控制算法进行仿真研究,并与传统PID控制算法进行对比。结果表明,所设计的控制策略实现了千吨级负载下多缸系统同步误差小于0.05 mm的稳定输出,具有较好的鲁棒性和较高的同步控制精度,为国产大吨位惯性摩擦焊机液压伺服系统提供设计参考。     

单神经元PID在多电机控制中的应用

本文通过对多电机同步控制的原理及其特点分析,设计了具有自学习和自适应能力的单神经元PID同步控制器,建立了单神经元PID控制规则,提出了多电机同步控制的单神经元PID学习算法。系统仿真结果表明,运用单神经元自适应PID控制器能有效实现多电机同步控制,收敛速度较快,鲁棒性较好,且抗干扰能力强。最后,基于MCF5235微控制器,通过VxWorks实时嵌入式操作系统,应用于四轴同步控制系统,结果表明单神经元自适应PID同步控制器能大大增强系统的动态性能,有效缓解负载带来的同步误差,在相同扰动情况下,该方法能更好的使多电机以一定速度同步运行。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.