共查询到20条相似文献,搜索用时 217 毫秒
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阐述了在220卧式镗铣床技术改造中数控系统与电器的设计思想和实现方法.介绍了SINUMERIK 810M数控系统对直流伺服电机变速驱动系统控制所实现的宽的调速范围、高的稳速精度、快的动态响应以及在四象限内运动等良好的技术特性;描述了该机床CNC控制的结构特点.该数控系统与电器的开发研制为机床的技术改造开辟了一条新的途径. 相似文献
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火电厂输煤系统中碎煤机的PLC控制 总被引:1,自引:0,他引:1
介绍了PLC在碎煤机控制和保护中的应用,简化了硬件结构并完善了保护系统,从而大大降低了设备事故率。论述系统控制要求与特点,给出了控制系统的方案设计和硬件组成框图。该设计针对生产中遇到的问题提出具体解决方案,具有实用性、可靠性和安全性。 相似文献
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为了提高小型随车起重机出厂起重性能测试的方便性和高效性,依照随车起重机自身的车载吊臂工作性能,设计了一种基于PLC控制的液压试验平台检测设备。根据随车起重机在工作中需要完成的动作和性能参数要求,设计了平台的电-液控制系统,描述了液压试验平台结合多传感器实时采集数据与PLC进行RS485通信的过程,并对液压系统中电磁阀电信号进行调控,以此检测随车起重机的起重性能状况。结果表明:应用设计的液压试验台对2 t和3.5 t小型随车起重机进行起重性能测试,其结果符合厂家设定的起重机性能参数范围。研制的液压检测设备采用触摸屏进行人机交互,界面操作简单、系统运行平稳,既保证了性能检测的准确度,又可以有效缩短检测周期,提高了出厂性能检测的效率。 相似文献
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Faced with the complexities of managing new product development, most of us would welcome the support of a computer-based system that captures the knowledge and the reasoning capabilities of experts in our field. Considerable effort has been focused on the design and development of expert systems for applications such as new product management. However, design and development are only two steps on the path to successful implementation of a useful expert system. A rigorous validation process is essential for ensuring that the expert system performs as intended. Using the INNOVATOR expert system as an example, Sundaresan Ram and Sudha Ram propose and test a framework for validating expert systems designed for new product management. The proposed validation framework considers three aspects of the expert system: its knowledge acquisition methodology, its performance, and its utility. Validation of an expert system's knowledge acquisition methodology involves assessment of the knowledge sources used, the criteria for selecting human experts, and the methods used for knowledge acquisition. Using multiple sources improves the likelihood that the expert system will capture the necessary core knowledge. Similarly, selection of the experts who are to supply the knowledge used by the expert system should be based on reliable measures of new product expertise rather than ad hoc measures. The system's performance is evaluated through formal tests of the accuracy and the completeness of the knowledge base, the consistency and the accuracy of the decisions made by the system, and the reasoning process by which the system reaches its decisions. Such tests may involve direct examination of the system by experts, and Turing tests, which compare both the recommendations and the reasoning process of the system with those of selected experts. Both types of tests may involve experts from whom knowledge was acquired during the development of the system as well as experts who were not involved in the design and development of the system. Assessment of an expert system's utility focuses on user perceptions of system performance and utility as well as the design of the user interface. First, end-users must evaluate the relevance of the chosen problem domain. In other words, the validation process must verify that the expert system addresses an important problem that requires decision support tools. Second, the expert system must provide a logical, systematic approach to solving the problem. Finally, the expert system must provide a consistent, intuitive user interface. 相似文献
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为了准确获取地铁线网短时OD(起讫点)的客流分布,从而高效协调运输能力和客运需求,结合集成学习思想构建了基于决策树模型的多时间粒度下地铁线网短时OD客流预测模型。首先利用地铁自动售检票数据分析得到线网OD客流出行的时空分布特征,引入多种时空影响因素对全网数据进行训练以及预测,其次分析了地铁线网OD客流量预测精度与时间粒度之间的关系,最后以苏州市地铁为对象进行实例分析。结果表明:相对于其他模型,研究模型不仅可以有效降低预测误差和拟合客流峰值,而且运算时间也节约了数倍,提高了地铁线网短时OD客流预测的准确性和效率。因此,所设计的模型可为地铁运营与控制系统提供重要数据,有助于运营者进行限流措施、行车计划等的制定与调整。 相似文献
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针对传统黏度计可调档位少,测量精度低、范围小等方面存在的不足,设计了一种基于旋转法的油墨黏度测量系统。系统以光栅转矩传感器作为数据采集装置,通过AT89S52单片机结合可编程逻辑器件(CPLD)搭建系统硬件平台。在软件方面,提出了一种基于恒力矩旋转磁场微步细分理论的步进电机多级细分驱动方法驱动电机,实现转速的多档连续调节,提高系统的黏度测量范围和精度。 相似文献
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张冉 《石油工业技术监督》2014,(5):21-24
HSE管理体系中,高压电机的安全运行具有重要的作用。通过振动监测高压电机运行状态的传统方法是采用3个单轴加速度传感器进行数据采集,故障诊断的准确性有待提高。将三轴加速度传感器应用于高压电机轴承的振动分析,实现3个方向的振动数据同时采集,简化了测试方案,提高了测试结果的准确性。分析了电机典型故障与电机电流频谱的对应关系,结合振动分析法对高压电机定、转子电气和机械运行状态进行监测和故障预警,从而保证油田高压电机的安全高效运行。 相似文献
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为了提高电力电缆的利用率,合理调配电缆的实时负荷,利用实时环境参数监测终端、GPRS数据传输模块和上位机构成了高压电力电缆实时载流量评估系统。并利用DS18B20、风力传感器、土壤温湿度传感器、光照传感器和STM32嵌入式单片机对环境参数进行实时监测,实现了对环境温度、土壤湿度、土壤温度、环境风力、环境光照等参数的实时采集,并利用GPRS数据传输模块将环境参数传送到上位机,利用上位机结合VB6.0和ANSYS编制了高压电力电缆温度场和载流量计算软件,实现了电力电缆参数数据库存储、敷设模式界面化操作、环境参数的实时监测与显示、实时动态载流量的在线计算等功能。计算结果表明,高压电力电缆的实时动态载流量系统能够准确计算出受环境参数影响的高压电力电缆的载流量,提高了计算效率,为电力部门调配电缆的实时负荷提供了依据。 相似文献
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采用先投入高串抗率电容器、后投入低串抗率电容器这种单一配置方案,导致变电站出现高串率电容器频繁投切、寿命降低和无功容量浪费问题。为了解决这些问题,提出一种基于阻抗估计和多电能质量约束的变电站电容器组优化配置方法。首先,获取电容器投切后公共连接点母线电压电流数据;其次采用小波最大最小阈值去噪,通过Prony算法得到暂态电压、电流数据来估计系统谐波阻抗,最后结合AVC下达的调度指令和目标函数在满足电网电能质量约束条件下对电容器组进行优化配置。结果表明,在满足电能质量约束和AVC调度指令下,优化配置后高低串抗率配置频次均有所改善,高串抗率电容器组投入频次下降32%,低串抗率电容器组投入频次由26%提高至58%。由系统谐波数据、谐波源和电容器等元件组成的谐波阻抗模型,以及基于谐波谐振机理设计的电容器组配置方案,能够提高数据分析的准确性,减小电容器损坏以及解决无功容量损失问题,提高供电质量,可为变电站电容器组的配置提供借鉴。 相似文献