基于AVR单片机的智能避障小车设计

本文介绍了以ATmega128A单片机作为主控制器,以超声波测距传感器HC-SR04为主要测距元器件,以两驱动的步进电机小车作为主体,设计出智能避障小车系统.步进电机驱动器采用L297和L298构成的混合式步进电机控制器.软件部分采用模块化程序,将距离的测量、避障算法、步进电机控制分为几个子程序,综合后实现智能车的避障功能,获得了较好的效果.     

用TWH8751集成功率放大器构成微机控制的三步进电机驱动电源

<正> 一、引言作为步进电机的驱动电源,以往大多采用分立元器件构成。功耗大,效率低,体积大而笨重。后来既使采用了集成环形脉冲分配器CH250,但它的负载能     

步进电机一体化控制系统的设计

本文应用单片机、步进电机驱动芯片、字符型LCD和键盘阵列,构建了集步进电机控制器和驱动器为一体的步进电机控制系统。二维工作台作为被控对象通过步进电机驱动滚珠丝杆在X/Y轴方向联动。文中讨论了一种以最少参数确定一条圆弧轨迹的插补方法和步进电机变频调速的方法。步进电机控制系统的开发采用了软硬件协同仿真的方法,可以有效地减少系统开发的周期和成本。最后给出了步进电机控制系统的应用实例。     

新产品与新系统

Allen-Bradley CompactLogixL45紧凑型控制器提供了扩展的运动和分布式控制功能;安捷伦科技推出业内最全面的LTE信号分析解决方案——帮助设计人量成功进行元器件和收发信机设计;轻盈、灵动的运动控制——贝加莱ACOPOSmicro小功率伺服电机和步进电机的驱动解决方案     

步进电机对位移驱动与测试的双重应用

随着步进电机在工业控制中的广泛应用,各种步进电机控制系统也相继问世。我们研制了一台功能材料的拉伸机,其中的动力机构就是一台步进电机系统,它的控制器是由89C52单片机来充当的。我们这台功能材料拉伸机的任务是用一台微处理器完成功能材料的特征性能参数应力、应变、温度及相变的数值采集、处理、显示和记录;并且可以按照受力、受热规程,对实验的应力(或应变)、温度的变化速率及目标值进行智能化反馈控制。具体是：把制备的形状记忆合金材料试样加装在拉伸机上,利用步进电动机加装载荷,同时运用制冷制热半导体可对试样进行…     

对步进电机驱动新方案的研究

新兴的计算机工业迅速将步进电机采用到外设应用当中。步进电机的主要优势在于能提供开环位置控制,而成本只是需要反馈的伺服系统的几分之一。通过分析步进电机几种常见的驱动方式,并研究了步进电机驱动控制中的关键技术,认真学习了东芝公司的大功率步进电机驱动芯片THB6064H的相关资料,在充分考虑步进电机在节能灯流程控制中的具体要求的前提下,本文通过实验仿真和应用实例,证明了该步进电机驱动方案简单、准确,有效。     

服装裁剪机的步进电机细分控制系统

针对服装裁剪机中步进电机的运动控制问题,基于LPC2138和L6207设计了步进电机细分控制系统,实现了对步进电机的高精度细分控制。实验结果表明,步进电机可以在细分控制系统的控制下稳定、准确的运行,满足了服装裁剪机的精度要求。     

基于云平台的智能电子元器件储存柜设计

针对电子实验室内存储电子元器件因型号多所引起管理和使用困难的问题，设计出一种基于中国移动Andlink平台的智能电子元器件储存柜。此系统主要由存储柜、通信模块、传感器模块、步进电机模块和安卓APP组成。能实现通过安卓APP远程操作储存柜，根据实际需求自动推出存储柜的抽屉。存储柜内所有电子元器件的存放信息均通过安卓APP自定义，并上传保存在云平台。智能电子元器件存储柜能够让用户方便快捷地找到需要的电子元器件，实时掌握电子元器件的消耗情况。     

步进电机及其单片机控制

随着工业自动化的发展,步进电机的应用越来越广泛.步进电机是一种用于开环控制的驱动元件.本文阐述了步进电机的基本知识和特性,提出了基于单片机控制和集成电路驱动的步进电机控制实现方法以及软硬件设计方法.     

基于AT89C52单片机的步进电机控制系统设计

提出了一个由AT89C52单片机控制步进电机的系统实例,可以通过键盘输入步进电机相关数据,步进电机根据这些数据来进行工作;并且可根据需要,实时对步进电机工作方式进行设置,具有实时性和交互性的特点;该系统可应用于步进电机控制的大多数场合.实践表明,系统性能优于传统的步进电机控制器.     

Relationship between trapezius muscle activity and typing speed: taping effect

Clinically, over-activation of upper trapezius (UT) muscular activity is a common cause of symptoms in computer users. The purpose of this study was to investigate the correlation between trapezius muscular activity and typing speed with and without taping. Twelve participants performed a typing task for 15 min with and without taping on the UT muscle. Electromyography (EMG) of the muscular activity of UT and lower trapezius (LT) was recorded. With or without taping, there was a significantly positive correlation (r = 0.40, p = 0.04) between typing speed and UT/LT. Additionally, UT and UT/LT ratios were lower with taping than without taping (difference = 5.2% and 26.9%). The LT ratio was higher with taping than without taping (difference = 5.8%). Taping can alter the muscular activity of the trapezius during typing and may have the potential to be applied in computer users to prevent over-activation of UT muscular activity.

Practitioner Summary: The effect of taping was tested on typing speed and trapezius muscular activity. With or without taping, typing speed was correlated with trapezius activity. The muscle activity of the trapezius, however, was lower with taping than without taping. Thus, taping has the potential to prevent over-activation of UT muscular activity during typing.     

传感器自动修调系统设计

传感器电路在生产流片中,受到工艺条件等非理想因素影响,一些参数偏离设计值,会导致流片后芯片精度及性能达不到设计预期。为弥补这一电路设计期望与芯片最终性能之间的差距、快速完成修调工作,通过系统、硬件、软件三个层面的详细论证,综合设计一款传感器自动修调系统。系统由控制板、修调电路板及上位机显示控制部分三大块组成,用到单片机及各种电路模块、传感器、外围电路等。上位机显示控制部分采用VB编写,界面简洁友好、操作简单。经实验调试,系统实现了多参数、高精度采集,能够快速完成修调工作,保证修调完的传感器满足性能要求。     

龙芯2号配套PCI Bridge的功能覆盖率验证

介绍了龙芯2号配套北桥中PCI Bridge的功能验证系统以及功能覆盖率建模和分析方法。该系统和方法在开发和验证PCI Bridge模块过程中发挥了重要作用，加快了PCI Bridge的开发速度，协助发现了一些设计与规范不相符合的地方，对后期流片成功提供了有效保证。描述的功能覆盖率建模和分析方法具有一定通用性，可以为其它相似系统的验证提供借鉴。     

Assessment of perceived traumatic injury hazards during drywall taping and sanding

The objective of this study was to identify the drywall finishing tasks which are directly perceived as hazardous by workers. A questionnaire survey was conducted to evaluate workers’ perceived injury hazards (physical stress, fall potential, and struck by/against an object) for six finishing tasks (4 taping and 2 sanding tasks) and three items of elevated support equipment. Thirty experienced drywall finishers participated in this study. The ratings of perceived physical stress and fall potential varied significantly among the six tasks (both p values <0.05). Subjects perceived greater physical stress for the two drywall sanding tasks than the four taping tasks. Sanding skimmed drywall without the use of pole sanders, in particular sanding ceiling joints, nails, and corners was rated most stressful. Wrists/hands and shoulders were identified as the most affected body part subject to physical stress during drywall taping and sanding. Tasks performed with the use of stilts were rated as having greater fall potential than those without using stilts. The activity of putting on stilts and getting up on them was most likely to cause loss of balance. Results from this study provide information directly from experienced workers to help identify hazardous tasks and activities associated with drywall finishing. The findings will assist in focusing future research efforts on the most hazardous tasks and activities of drywall finishing.Relevance to industryConstruction workers who perform drywall installation, including taping and sanding drywall sheets, have the highest incidence/injury rate compared to any other workforce. Taping and sanding drywall sheets increases the potential for physical stress, falls and struck by and against objects. A questionnaire was designed to collect injury information directly from painters who performed drywall taping/sanding and to identify perceived hazards associated with drywall taping and sanding. Prior to this study, there has been little substantive research to ergonomically evaluate the excessive stresses and potential injuries imposed on this workforce.     

Flexible telemanipulation based handy robot teaching on tape masking with complex geometry

Traditional robot teaching methods are cumbersome, tedious and difficult to scale for high-mix low-volume applications. The tape masking, a common process for surface protection before plasma spraying, spray painting and shot peening, is one of those domains where robotic automation lacks flexibility and reliability due to the complexity in task. Fortunately, it is still within the grasps of human-robot collaborative systems. This work presents a telemanipulation-based robot teaching framework that is able to let the robot manipulator cope with the taping tasks with complex workpiece geometries. The proposed framework allows quick calibration, variable motion mapping, and indexing so that the operators can easily set up and guide the robotic taping system to cover the tapes onto the layers and grooves of different workpieces. This framework enables the operators to change the motion mapping scale for both large-scale guidance and fine motion dexterous manipulation. Meanwhile, an indexing function makes it possible for the operators to re-map their poses from the edges of their comfortable regions. A portable VR system is applied in the telemanipulation system. With its six DoF motion precisely measured in real-time, the proposed motion remapping algorithms enable the operators to directly guide the robot in their selected scales. Experimental results show that the proposed framework facilitates robot programming on the manipulation of the complex workpieces that have multi-layer surfaces and grooves in between. It also reduces the teaching time comparing to other methods. This system and method improve teaching efficiency and convenience, which has potential value to be deployed in manufacturing.     

ARINC659总线协议芯片的仿真验证

在现代集成电路设计中,对芯片的仿真验证是芯片设计验证的关键环节之一,一定程度上决定流片的成败。为了搭建一种可靠的芯片验证的虚拟平台,首先分析了ARINC659总线协议的特点,在此基础上结合ARINC659总线协议芯片设计中基于虚拟验证平台的仿真验证项目实践,重点研究了该芯片设计虚拟验证平台的一种构建实现方法和仿真验证。该验证方法提高了验证效率,缩短了整个设计验证周期,为芯片的成功投片提供了可靠的保证。     

多总线接口信号处理SoC虚拟验证平台的实现

多总线接口信号处理SoC芯片是以信号处理DSP为核心集成了多个总线接口的片上系统,该SoC涉及的总线协议众多,验证复杂、工作量大,验证将是该SoC芯片开发的瓶颈。为了缩短多总线接口信号处理SoC芯片的开发周期,提高该SoC芯片的一次流片成功率,必须采用更为可靠和有效的验证方案。以SoC验证流程及方法为指导,重点介绍了多总线接口信号处理SoC虚拟验证平台的构建和具体实施。验证结果表明,该验证平台能高效、全面验证芯片功能,提高了芯片验证效率,缩短了整个芯片开发周期,为芯片的成功投片提供了可靠保障。     

内嵌ARM9E内核系统级芯片的原型验证方法

随着大容量高速度的FPGA的出现,在流片前建立一个高性价比的原型验证系统已经成为缩短系统级芯片(SoC)验证时间,提高首次流片成功率的重要方法。本文着重讨论了用FPGA建立原型进行验证的流程、优缺点以及常用方法,并结合对一款内嵌ARM9ESoC1所进行的原型验证,说明这一方法在SoC验证中的应用。     

一种基于基准电压的高速IO

本论文提出一种通过基准电压来减小延时的IO 设计方法,设计出具高速特性的IO 模块,从而满足高速 SRAM产品的使用需求。该模块主要的设计思路为：通过基准电压提供一个中间态电压,通过中间态电压快速响应,减小IO 的延时。通过HSPICE仿真表明,这款电路能满足200Mhz SRAM 需求,并通过流片,验证此结构是可行的。     

融合上下文信息与核密度估计的协同过滤推荐

随着互联网信息技术的迅速发展,网络数据量快速增长,如何在海量数据中找到用户感兴趣的信息并实现个性化推荐是目前重要的研究方向。协同过滤算法作为推荐系统中的经典方法被广泛应用于不同场景,但是仍然存在数据稀疏,以及在计算相似度时不能考虑到所有数据的问题,只能够利用具有共同评分的数据,严重影响了推荐的精确度。针对上述存在的问题,提出了一种融合上下文信息与核密度估计的协同过滤个性化推荐算法。该算法通过对用户和项目各自的上下文信息和已经存在的用户评分数据进行处理,通过核密度估计构建用户和项目的兴趣模型,充分挖掘了用户和项目的兴趣分布,以获得更准确的用户和项目兴趣相似度,降低预测评分误差。在公开的数据集上验证表明,将该算法对比传统的协同过滤算法,有效提高了推荐的精确度。