共查询到20条相似文献,搜索用时 171 毫秒
1.
针对复杂顺序控制设备,提出了一种计算机辅助分析和功能模块分析相结合的顺序控制梯形图分析法,并给出了应用实例。 相似文献
2.
本文讨论了CENTUM集散控制系统的顺序控制功能,在对苯二甲酸二甲酯结晶过程控制中的应用,对结晶过程中的加料、膨胀、中间冷却、冷却、排料和冲洗等过程的顺序控制进行了深入地分析,并给出了顺序控制功能的实现。 相似文献
3.
本文以欧姆龙CJ1M为例,用两种不同结构的顺序控制实现了人行道交通灯系统的控制,并对顺序控制中的小循环问题给出了解决方案.通过分析,指出对具体的控制对象,顺序的结构可以灵活变化. 相似文献
4.
余峰浩 《机械工程与自动化》2011,(5)
以典型气动机械手控制为例说明了移位指令在PLC顺序控制中的应用方法。对比了几种常见的实现顺序控制的编程方法,指出了采用移位指令实现顺序控制的优点,并用实例说明了其具体程序的实现方法。 相似文献
5.
阐述了顺序控制中采用EDA技术的优点.以气缸的往返运动为例,说明了EDA技术应用于顺序控制中的可行性,详细给出了基于状态机设计的气缸往返运动的VHDL语言程序及仿真波形.仿真结果及现场调试表明,EDA技术可适用于顺序控制过程中. 相似文献
6.
7.
SFC在洗衣机控制设计中的应用 总被引:2,自引:2,他引:0
介绍了PLC顺序控制的编程方法,以与三菱PLC兼容的小型PLC为实际控制器,阐述了如何实现PLC对全自动洗衣机的顺序控制和循环控制。 相似文献
8.
9.
10.
阐述了顺序控制中采用EDA技术的优点。以气缸的往返运动为例,说明了EDA技术应用于顺序控制中的可行性,详细给出了基于状态机设计的气缸往返运动的VHDL语言程序及仿真波形。仿真结果及现场调试表明,EDA技术可适用于顺序控制过程中。 相似文献
11.
为提高复杂产品的分析模型和知识的重用,提出了复杂产品数字样机构件化分析方法.该方法以分析元作为分析知识、模型和信息等相关内容的基本组织方式,以分析树作为分析元层次结构及相互关系的组织方式.在分析复杂产品层次化结构的基础上,研究并构建复杂产品层次化信息模型和构件化分析信息模型,作为复杂产品分析信息的组织和处理的基本机制.研究并形成产品构件化分析的实现技术,包括构件化分析过程、信息模型构建、关键参数识别、性能目标约束方法等.最后以水轮发电机为例,进行构件化分析的实现. 相似文献
12.
13.
14.
15.
16.
A numerical prediction of the transient fuel temperature in an aircraft was made and verified with a flight test. The analysis was studied with the finite difference method. Numerical calculation was performed by an explicit method of the modified Dufort-Frankel scheme. Convective heat transfer coefficients were used in calculating heat transfer between the aircraft surface and the ambient air. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And, the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. The analysis was verified with the flight test data of a fuel system with additional fuel supplies and return concept. As a result of the verification, the difference of the fuel temperatures obtained by the analysis from those of the flight test data was relatively small with a tendency to increase in the later phases of the flight. 相似文献
17.
18.
This paper presents a combined analysis for the rotor and dynamic components of a rotorcraft. The dynamic components consist of the following elements: a rotor shaft, a drive train, the engine shafts, and an engine and its governor. In this paper, the dynamic components were developed in a modularized fashion and combined with the rotor analysis. The present rotor structural analysis was derived based on the mixed variational formulation of moving beams and combined with finite-state dynamic inflow aerodynamics. A linear mass-spring-damper connection was used for a drive train representation and a simple linear control algorithm was used for an engine governor. To analyze the response of the components, a state-space equation was established based on the torque equilibrium. The present multi-component structural and aerodynamic analysis was solved for by measuring the steady-state trim and time-transient response. Numerical validation was performed using a sample hingeless rotor in a tiltrotor aircraft. The present prediction showed good agreement with CAMRAD II for both the trim analysis and the transient analysis with the trimmed state. And distinctions between the rotor with and without dynamic components were verified. Thus, an accurate framework for the rotor system including the dynamic components was developed, which would be useful during the preliminary design stage of creating a rotorcraft. 相似文献
19.
20.
贝叶斯网络分析方法是可靠性分析的重要方法,但传统贝叶斯网络分析方法局限于分析单因素影响,当系统可靠性受多因素影响时会产生较大分析偏差。为此,提出多维动态贝叶斯网络分析方法,借助单位阶跃函数与冲激函数进行贝叶斯网络时间连续化构造,建立根节点受多因素影响时系统的失效概率分布函数。在此基础上,对传统重要度分析方法进行多维扩展,提出多维动态贝叶斯网络重要度分析方法。通过对斗轮机张紧机构液压系统进行工程实例分析,并与离散时间贝叶斯网络分析方法分析结果对比,验证了多维动态贝叶斯网络及其重要度分析方法的可行性和优越性,为系统改进与薄弱环节识别提供了更为准确的量化依据。 相似文献