基于PLC的步进电机速度控制的仿真研究

提出了一种基于三菱FX2N系列可编程控制器(Programmable Logic Controller,PLC)的控制步进电机速度的方法,主要研究了利用PLC实现对步进电机低速、中速、高速运转的控制,还实现了根据控制要求步进电机可以完成不同步数运转。     

大功率步进电动机的控制驱动电路

采用NE555设计步进电机脉冲产生电路，对EPROM2716进行编程实现脉冲环形分配，并决定四相八拍或四相四拍的驱动方式，电动机的运行方向由74LS191的D1J控制，设计了高低压驱动电路，减少了限流电阻的发热。     

基于单片机的步进机控制研究

本文首先对步进机进行了深入的概述,然后给出了基于单片机的步进电机控制.通过采用单片机AT89C51和脉冲分配器PMM8713控制步进电机在三相六拍工作方式下的启停控制,正反转控制和加减速控制.最后对步进机的运行控制进行了详细的分析.     

基于PLC的步进电机的驱动控制

介绍了应用三菱PLC实现三相三拍三拍步进电动机的控制方法,给出了具体的应用电路和参数.经过测试、应用,该广场法对步进电机的控制精确、可靠,具有一定的应用和推广价值.     

提高磁盘驱动器容量的方法

随着计算机用户运用技术的提高,处理的信息量增大,就感到计算机所配的磁盘驱动器容量不够。我们对目前应用较广的18MB、IMI5.25英寸磁盘驱动器进行了改进,把容量提高了一倍,且花费较少。提高容量措施主要是设计控制步进电机走步的电路和软件,换用铁芯为27μm的磁头。一、提高驱动器容量方案 IMI5.25英寸磁盘驱动器的道密度为300TPI,步进电机步距角为0.9°,且以双四拍方式工作。如果我们控制电机以单八拍方式工作,就能把道密度从300TPI提高到600TPI。我们采取增加一块新的单片微机8749的方法实现电机单八拍走步及伺服控     

基于单片机控制步进电机细分驱动的实现

分析了等电流法和电流矢量恒幅均匀旋转法两种细分驱动方法，提出了基于单片机控制的电流矢量恒幅均匀旋转的细分驱动技术。实现了两相四拍混合式步进电机细分驱动。为了补偿步进电机相绕组电流与其产生磁场之间非线性引起的误差，采用了最小二乘法对细分步距角误差曲线进行了拟合与修正，提高了细分精度。     

毫米与步数转换程序的设计

在传统的机械加工中,控制加工量是靠人直接操纵设备按钮、手柄等,由丝杆带动刀架或工作台的移动和升降来实现的。采用由计算机控制的机械加工,往往是由程序控制步进电机从而带动丝杆的转动来实现。所以,使用计算机控制机械加工的设备,在编制控制程序(用户程序)中,普遍存在着一个如何将程序输入的加工量(毫米)转换成步进电机的脉冲步数问题。为此,我们设计了一个能适于用步进电机带动丝杆控制加工量的毫米与步数转换程序。     

改造线切割机床应注意的问题

在一些较早的线切割机床上多采用分立元件线切割控制器,由于其功能远不如微机线切割控制器,所以有些厂家已用微机线切割控制器对这些机床进行了改造,但大多数厂家由于技术上的顾虑不敢改。其实这种改造并不难,只要注意以下几个方面,就可顺利地对原机床进行改造。 (l)根据机床步进电机是单六拍还是双三拍来合理选择微机控制器,保证微机控制器的驱动方式与步进电机绕组的通电方式一致,否则步进电机会失步。当然,有的微机控制器已用软件将驱动方式置为双三拍和单六拍,此时用户用按键选择即可。 (2)如图所示,根据步进电机功放线路中未级管BGI…     

调整步进电机驱动电路的一种简易方法

数控机床广泛使用步进电机作为执行元件,步进电机的驱动电路普遍采用高低压切换供电方式,其功率级一般如图1所示。 调试驱动电路时,一般用示波器观察电机各相绕组上的电压波形,并调节各相高压作用时间达到基本一致。在实际运行中,经常发现步进电机处于较高频率下工作时,会出现不明原因的“失步”现象,丢失的步数为步进电机工作拍数的整数倍。例如六相12拍运行的步进电机,“失步”数为12步, 24步,36步……,而且这种“失步”是随机的,并不每次出现,因此给调整和维修增加了困难。为此,有时不得不降低工作频率,从而使系统的快速性受到限制,降低…     

微型计算机对步进电机可变细分控制

步进电机是一种将脉冲电信号转换成角位移或转速的精密执行和驱动元件,广泛应用在自动控制系统中。步进电机控制器则是驱动步进电机的脉冲电信号源,与步进电机是一个有机整体。随着集成电路的迅速发展和微型计算机的普及,为步进电机的控制开辟了广阔的天地。近几年来,应用TP801单板微型计算机控制步进电机,灵活方便,简单可靠,很轻易地实现正、反转控制,速度控制和步数控制。用户可以根据自己的用途和要求,用微     

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。     

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。     

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.     

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...     

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。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.