嵌入式系统的多路步进电机控制系统的设计

设计并实现了一种基于FreeRTOS的多路步进电机控制系统,运用于小型流水线。系统控制电路采用STM32F4系列的微控制器,结合小功率步进电机驱动器A4984以及嵌入式以太网控制器W5500,完成硬件设计,后对其进行软件开发,设计出可以实时控制并改变电机脉冲起始频率、最大频率、电机转动方向、电机脉冲总数、加速脉冲数以及减速脉冲数等参数的上位机模块。在电机驱动中加入改进型S型算法,有效的优化步进电机初始速率增加过快导致的步进电机失步和过冲现象。在实际项目的验证过程中,证明该系统具有良好的稳定性。     

FPGA的多通道步进电机控制系统设计

提出基于FPGA的多通道步进电机控制系统。首先，改进步进电机梯形加减速算法，降低其计算过程的复杂度；其次，对改进的算法在FPGA硬件平台上移植；最后，使用上位机的可视化操作界面与FPGA控制端共同搭建一套灵活的控制系统，使得参数可在上位机端实时更新配置。实验结果表明，该控制系统能够对电机启停频率进行精确控制，各阶段频率误差在2%以内，且不会出现失步与过冲现象。     

基于PID的自动台球机安全运球控制系统的设计

为解决打台球收球、摆球的繁琐性,提高台球机娱乐性能,设计一种可以自动实现台球摆送台球的装置,为实现台球可以安全准确地将台球运至摆球位置,以STM32F407作为系统控制核心,以MC442两相数字式步进驱动器作为步进电机驱动器,驱动装置运行,并使用PID算法控制步进电机实现加减速缩短运球时间,并增添蜂鸣器作为安全预警器,通过调整PWM控制步进电机进行点动,并伴随预警器提醒人们避让保持运行轨迹的畅通,在位置关键点设置接近开关解决步进电机失步的问题保证运球的精确度.     

可实现多轴同步运动的驱动设计

在实际使用过程中步进电机的使用往往不是单个出现使用,多驱动器会导致控制部分体积过大,增加自身重量,移动不灵活等问题产生。本文设计的驱动器可以实现同时控制多台同类型号的步进电机运动,并且通过仿真实验验证了设计不仅符合四相步进电机的驱动原理,亦可制版投入使用实现多轴步进电机单拍运动方式控制驱动。     

基于AMIS30522的步进电机控制器设计及实现

越来越多的加工、汽车、安全和建筑自动化应用依赖步进电机提供动态运动,新型步进电机驱动器使得设计人员能够用最少的元件和最低的材料成本,快速而简便地完成动态运动应用.本设计方案中采用具有10位A/D转换器的低功耗MsP430F2012为核心控制器,选用新器件AMIS-30522作为步进电机驱动器.实际应用显示,此设计具有结构简单、多级细分、控制灵活以及工作稳定可靠等特点.     

步进电机加减速曲线优化设计与仿真

加减速算法在步进电机开环控制系统中发挥着关键作用,传统梯形、抛物线形加减速算法由于在加减速过程的起点或者终点存在加速度突变,易给电机运行带来冲击。针对上述问题,设计了一种基于正弦函数的新型S形加减速算法,此算法更加符合电机转矩特性,并依据两相混合式步进电动机的数学模型以及细分驱动原理,在MATLAB仿真环境下搭建了步进电机开环控制模型。仿真结果表明,该算法能够保证电机运行过程中加速度的连续变化,减轻了步进电动机柔性冲击,提高了电机的控制精度和运行稳定性。     

步进电机加减速控制技术研究

文章主要介绍了步进电机加减速控制技术,分析了步进电机短距离加减速控制的特殊性,提出了加减速控制方案,同时也分析了整机运行过程中产生的共振现象及其解决方法。     

基于STM32的步进电机速度控制方法研究与实现

在机器人电机控制过程中,发现带载情况下如果电机起步速度过快会导致电机堵转问题,很需要一种可以实现电机匀加速的精确控制方法。本文借助于STM32F103,通过其I/O口输出矩形波脉冲序列的方式控制步进电机驱动器或伺服驱动器,从而实现对步进电机的位置和速度控制。通过修改定时器值实现梯形加减速轨迹,使步进电机运行具有较好加减速性能。另外,由于STM32F103芯片具有多路定时器,可以通过配置多路定时器输出多路不同频率的脉冲信号,实现对机器人多轴(多个电机)的控制。该方法对于机器人嵌入式步进电机控制器的开发具有很好的参考价值。     

基于Δcos(φ)/ΔI因子的步进电机驱动电流优化控制研究

脉冲步进指令控制的传统步进电机具有开环定位的特点，无需位置传感器。而开环控制的缺点在于当发生过载时容易导致失步，为了降低失步发生的概率，步进电机通常以最大电流工作，这会影响其工作效率。针对上述问题，提出了一种基于Δcos(φ)/ΔI因子的优化步进电机驱动电流的控制算法，该算法结合步进电机的特性及其步进指令脉冲，适用性强，计算过程简单，无需额外设置步进电机的机械或电气参数。利用混合式步进电机的实测数据进行了数据仿真实验，证明了所提出算法的有效性。     

LabVIEW控制步进电机自动升降速

步进电机在开环控制系统中作为控制用电机和驱动用电机得到广泛使用,为防止失步和过冲,使用步进电机高速运行时必须有升降速过程。本文在分析比较几种常用的升降速控制曲线基础上,利用LabVIEW通过PCI-1780卡实现了步进电机自动升降速的软件控制。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate