单片机在地热综合利用中的应用

本文以单片机实现对地热温室分布式控制为例,说明地热综合利用中应用单片机的方法。该系统包括一个主机和多个从机,主—从机间采用串行通讯。主机负责地热点的检测和管理,从机完成现场的数据采集和控制。文中介绍的方法也适用于粮仓、冷库和一般温室。     

高科技产品LED大屏幕智能显示屏

文中介绍由单片机或PC机控制的LED大屏幕智能显示系统的整机电路原理、主机工作程序及PC机控制程序     

智能卡灌溉自动控制系统

智能卡灌溉自动控制系统是山东省莱芜市电器厂针对目前国内农田灌溉现状研制成功的高科技产品,可广泛用于提水灌溉的水费自动计量、征收、机泵的自动开停,实现无人值守。本灌溉自控系统由一台安装在管理室的主机和多台安装在机泵旁的分机组成。该系统每一用户持一张智能卡.用户只要持卡到主机上交足额水费,主机将水费输入卡中,插入机泵旁的分机,按存取键,即可开机上水。机泵开始按水量、时间计量水费,每分钟显示1次,当灌水完毕按关机键或卡中无款便自动关机。本卡可长期反复使用10万次。目前农田灌溉争水、抢水、浪费水的现象     

智能化可燃气体泄漏检测报警系统的设计与实现

该系统为智能化可燃气体泄漏检测报警系统,可对现场的气体浓度进行实时监控,当气体浓度超标时,及时报警并启动通风设备,预防恶性事故发生。该系统使用Visual Basic和SQLSever 2000进行设计,详细介绍了系统实现的硬件、软件、数据库设计以及远程控制结构。     

选矿厂数控自动加药机

选矿厂数控自动加药机主要由主机、工控软件(WINCC6.2)、PLC、加药装置和电磁阀组成,简述控制原理、软件组态以及日常维护内容。     

大型油罐主动安全防护系统设计分析

针对大型油罐的结构特点以及其工作运转的基本原理,通过实时的气体分析与惰性气体联合保护的双保险同步防护的形式来设计大型油罐的主动安全防护系统,可以有效的提高大型油罐的安全系数。此安全防护系统主要由控制系统、检测系统、供氮系统、管网系统以及其他配套链接系统组成。其主要原理为在大型油罐的密封区域安装可燃气体泄漏检测系统,同时配套惰性气体保护系统,在检测装置检测到可燃气体的浓度超出预定阈值时,惰性气体系统自动打开并注入惰性气体氮气,从而阻止火灾或爆炸事故的发生。此安全防护系统成本低,检测灵敏且运行稳定,可有效起到安全防护的作用。     

成品高架库入库流量监控系统的设计与实现

针对成品高架库件烟流量过大引起的生产问题,设计一套远程实时管理的流量监控系统。系统利用扫码技术对成品件烟进行一号工程码扫码,同时通过视频手段对件烟流量进行动态监控,并将以上两路信号从生产现场传送至中控室PC主机,由主机的开发工具Powerbuilder进行数据采集、存储、处理,通过中控大屏实时显示,并由报警灯警示,实现件烟入库流量的远程监管。     

AS-I总线故障维修实例

AS-I网络由主站、从站、电源以及网络部件构成,主站由AS-I主机和控制器组成,机床AS-I通过网关连接到更高层的PROFIBUS总线中。网关作为AS-I主站的同时也作为高层网络的从站,大型复杂的分布式监控系统采用此方式。     

天然气分析系统操作评价的标准化

本文以ＩＳＯ／ＤＩＳ１０７２３文件为基础，从试验气体制备，系统有效性试验，重复性试验，响应值／浓度关系以及组分分离与干扰等方面讨论了天然气分析系统操作评价标准化的主要要求。     

压铸机压射机构液压系统常见问题处理

SCD系列冷室压铸机是瑞士布勒(BUHLER)公司的产品，由于其压射机构性能独特，压射过程由计算机实时控制，操作、监控界面友好等特性，在国内铝合金压力铸造行业得到越来越广泛的应用，国内汽车和摩托车发动机压铸件制造中引进了不少该系列的压铸机。压铸机系统由主机、自动上料系统、喷涂系统、取料系统等组成，由机、电、液、气和自动检测等技术组成的一个复杂的自动化程度很高的现代压铸机。压射机构又是整个压铸机的一个关键而特殊的系统，其工作性能的好坏对产品零件的质量影响重大。     

印刷质量过程控制技术发展趋势

本文综合国内外印刷过程控制技术的发展,对当前采用的印刷过程控制技术进行了综合论述。由于颜色测量技术的发展以及图像采集和处理技术不断成熟,这些技术可以应用在印刷机上进行印刷过程控制。通过图像采集技术实现印刷过程中印刷状态信息的实时采集和处理,并将信息反馈给印刷机控制机构实现印刷过程的闭环控制,有望代替目前印刷机已经沿用几十年的CPC墨色控制系统。     

Machine repairing models for production systems

In this paper we consider manufacturing systems of m identical unreliable machines producing one type of product. The operating time of each machine is exponentially distributed. The repairing process of a machine requires more than one phase. In each phase, the repair time is exponentially distributed and more than one operator may be required for fixing a broken machine. Here we consider two models of manufacturing systems. In the first model, there are r operators assigned in one server to repair a broken machine. The repairing rate in each phase depends on the number of operators there. This is a generalized model discussed in Buzacott and Shanthikumar [11]. We then consider a two-phase repairing model. Two groups of operators are assigned in the two phases. Each operator can handle one broken machine in each phase individually. This model is a generalization of Eben–Chaime's model [8]. Average profits are derived for both models and can be optimized by suitable allocation of the number of machines and operators in the systems.     

A Solution Methodology for Probabilistic Capital Budgeting Problems Using Complex Utility Functions

Historically, the study of economic equipment replacement is primarily limited to that of a single machine or a single machining system. The replacement situation whereby machines under consideration are part of a large integrated system has received little attention. This paper proposes a framework, for the analysis of multiple-machine replacement within an integrated system context. The major difficulty of analyzing such a problem lies in the interactive nature of an integrated system; that is, how should the effects to the entire system be assessed as a result of alterations to one or more of its components. The emphasis of this work is on the issues regarding multiple machine replacement. A single-period model is utilized in order to simplify the presentation. A comprehensive example is also provided for illustration.     

Modeling the response capability of a production system

This work is aimed at investigating the impact of labor flexibility and machine flexibility in the response capability of a production system in the clothing industry. To do this the response capability of a production system is modeled as a function of different flexibilities. From this model a 3² factorial experimental design is configured, which is implemented in the Arena 7.01 simulation language. The results show greater importance of machine flexibility compared to labor flexibility for the types of variability studied, and the performance of a production system when a high level of flexibility is used is similar to that in which a medium level is used.     

摩托车单向器自动装配机气动系统设计

针对当前摩托车单向器组件主要采用手工装配、装配效率低、随机性大、无法对装配过程实现有效管理控制的情况,为了易于对零件装配过程进行实时监测和提高生产效率,开发了一种智能摩托车单向器自动装配机。介绍了摩托车单向器自动装配机的上料系统、装配系统、检测系统和落料系统的机械结构,重点阐述了设备的气动系统设计,并进行了实验研究。结果表明,该设备可实现组成单向器的5种零件自动上料和装配,同时降低了操作人员的劳动强度,生产效率提高约50%。其气动系统噪音小、工作可靠,可应用于摩托车单向器的大批量生产。研究结果可为其他相似异形零件自动装配机的开发提供参考。     

Simultaneous control of production, repair/replacement and preventive maintenance of deteriorating manufacturing systems

This paper presents a method to find the optimal production, repair/replacement and preventive maintenance policies for a degraded manufacturing system. The system is subject to random machine failures and repairs. The status of the system is deemed to degrade with repair activities. When a failure occurs, the machine is either repaired or replaced, and a replacement action renews the machine, while a repair action brings it to a degraded operational state, with the next repair time increasing as the number of repairs increases as well. A preventive maintenance action is considered in order to improve the reliability of the machine, thereby reducing the amount of disruptions caused by machine failures. The decision variables are the production rate, the preventive maintenance rate and the repair/replacement switching policy upon machine failure. The objective of the study is to find the decision variables that minimize the overall cost, including repair, replacement, preventive maintenance, inventory holding and backlog costs over an infinite planning horizon. The proposed model is based on a semi-Markov decision process, and the stochastic dynamic programming method is used to obtain the optimality conditions. A numerical example is given to illustrate the proposed model, and a sensitivity analysis is considered in order to confirm the structure of the control policy and to illustrate the usefulness of the proposed approach.     

单片机控制LED显示屏动态显示的设计

介绍了一种利用AT89C52单片机控制LED显示屏的设计方案,使显示屏具有动态显示功能,并能通过上位计算机修改显示内容,通过标准的RS232/485转换模块还可以实现对显示系统的远程控制.     

中国制造业企业对“一带一路”国家OFDI模式选择的实证分析

本文以东道国的视角分析中国制造业企业对外直接投资（OFDI）模式选择的影响因素,并采用二元Logit模型进行实证分析。结果表明：“一带一路”国家的市场潜力越大、基础设施情况越好、自然资源禀赋越丰裕,中国制造业企业越倾向于选择绿地投资模式;而“一带一路”国家的技术水平越高,中国制造业企业越倾向于选择跨国并购模式。政府应提高海外投资信息服务水平,为企业深入了解东道国环境从而做出正确的投资模式提供便利。