步进电机闭环控制系统的研究与应用

针对步进电机在实际开环运行过程中,由于惯性作用、速度突变或者突加负载的时候易发生失步的问题,对步进电机的数学模型和速度控制数学模型进行了分析研究,对步进电机控制方法和控制算法进行了归纳分析,提出了一种带有光电传感器检测角位置的步进电机闭环控制系统。算法方面采用模糊PID控制策略对步进电机的输出特性进行了优化控制,最大限度地复现了预设的角位移量运行;同时选用指数运行规律的速度控制方法对步进电机进行了有效控制,为了便于微控制器实时处理并对其速度控制规律进行了离散化操作。研究结果表明:闭环控制系统在速度和负载突变时能可靠地避免失步发生,提高系统的精度、可靠性、动态性能和鲁棒性。     

无刷直流电机两种测速方法研究

对于无刷直流电机的稳速和调速系统,性能优越的速度检测措施是电机转速闭环控制的关键。文中介绍了基于霍尔信号的两种测速方法——频／压转换测速法和霍尔测频测速法,阐述了两种测速方法的原理,建立了无刷直流电机闭环控制系统的Matlab仿真模型;通过对计算及仿真结果的分析,对比了两种方法的测速性能及应用场合,为工程实践提供有力参考。     

步进电机升降速曲线的研究

本文从步进电机的动力学模型和矩频特性出发,推导了步进电机的理想升降速变化规律曲线及其实现方式。经实验证实,按这种升降速曲线,可以提高步进电机升降速速度,在高变速运行时不产生失步。     

步进电机速度控制的软件设计方法

介绍数控系统中步进电机速度控制的软件设计原理，并提出了使步进电机获得最高运行速度的软件设计方法。     

带电高空接过引线自动手臂自适应细分运动控制系统设计

针对高压电网接引线机械臂绕线和进给过程中,其步进电机存在速度突变和宽广范围内速度平滑控制问题,设计了以STM32F103系列微控制器为核心的运动控制系统,该系统采用自适应细分控制算法,解决接引线机械臂步进电机在低频运行时转矩脉动、细分切换引起速度突变和宽广范围内速度平滑控制问题.通过对接引线机械臂步进电机运行试验,证明了所设计的模型与运动控制方法的可行性.     

EP-501S型电动喷涂机器人开发与应用

EP－501S型电动喷涂机器人是步进电机驱动的五轴关节型的，主要应用对象是适用于中小型机电产品、陶瓷类产品及较复杂表面的油漆、塑粉、釉料等的喷涂。该机器人包括操作机和控制柜两大部分，其五轴关节操作机用混合式步进电机驱动，实现位置移动和姿态的变化。众所周知，步进电机的工作原理是给一个脉冲电机走一步，电机的角位移正比于所给的脉冲数，而电机的速度正比于脉冲频率，所以对步进电机的控制归根结底是对脉冲数的控制——位置控制和脉冲频率的控制——速度控制。在试验研究基础上，解决了混合式步进电机的基数PWM恒流驱动控制…     

基于单片机的步进电机控制系统实用设计

分析了步进电机的基本原理及其控制系统的功能,详细介绍了基于AT89C52单片机的步进电机控制系统的设计方案、硬件设计及程序设计。该系统可以实现步进电机正转、反转、加速、减速以及速度实时显示等功能,设计思路明确、可靠性高、稳定性强。     

光纤定位单元的微型步进电机速度控制优化

步进电机速度控制S曲线随电机型号及外力负载不同而改变。在获取光纤定位单元所用步进电机速度控制S曲线时,对传统S曲线生成方法进行优化和改进,采用三次方程的S曲线。通过对光纤定位单元进行走位实验,对比发现定位精度有了明显提高。该方法不仅能够很容易获取不同步进电机在加减速控制中的S曲线,而且在S曲线等脉冲离散过程中,可以跳过共振带而获得最佳曲线离散频率组,适用性好。     

数字式进给驱动系统的频响特性分析

介绍了一种采用步进电机作为驱动元件的进给驱动装置 ,为了消除步进电机所固有的量化误差 ,对步进电机采用一种连续跟踪的控制方法实现步进电机输出角位移的连续可控。对于连续跟踪控制下进给机构步进电机的“速度饱和”非线性引入描述函数的分析方法 ,研究其频响特性     

高效液相色谱仪恒流泵电路设计

目前我国生产的恒流泵均采用步进电机做驱动部件,它的缺点是脉动大,噪声大,本文叙述了用直流力矩电机测速机组取代步进电机控制电路的设计,介绍了改进后恒流泵的性能指标,显示了这种泵的优越性.     

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...     

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。     

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。     

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.     

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.     

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。     

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.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...