基于PLC电气控制在数控系统上的应用

针对传统数控机床采用的继电器控制,对比分析证明了采用PLC控制的优点。以搬运机械手在机床上的控制为例,介绍了采用PLC实现控制的方法,包括控制总体方案、PLC选型、控制原理及梯形图的设计。试验结果表明,该控制系统能达到预定控制要求,灵活性和可靠性得到提高。     

降低PLC控制系统成本的方法

PLC技术作为现代工业控制的一项重要技术。广泛应用于各行各业和生产的各个环节．受到普遍的关注和重视。伴随着应用领域的深入．PLC系统的价格越来越成为人们关注的焦点。有效地控制系统的费用将极大地促进这项技术的普及。结合应用实践从硬件和软件两个方面介绍了降低PLC系统成本的方法，提出了一些设计技巧。并借助原理接线图和梯形图不同形式作出具体的分析．这些技巧在应用PLC系统的过程中，具有很好的实用价值。     

基于多叉树的梯形图向指令表转换算法

针对目前可编程逻辑控制器(PLC)编辑软件中梯形图向指令表转化算法的缺陷,通过对梯形图语言的分析与研究,并考虑到梯形图和指令表在实际应用时的优劣点,提出了一种借助多叉树来实现PLC梯形图向指令表转换的算法;该算法采取从左至右,从上至下的扫描原则将梯形图构建成多叉树,借助多叉树来反应图符间的逻辑关系,然后通过后序遍历多叉树来得到指令表程序;此算法在处理多重串并联结构梯形图时具有更高的效率,同时适用于堆栈指令,使得该算法具有更好的通用性。     

Design and Implementation of a Flexible Manufacturing Control System Using Neural Network

Design and implementation of a sequential controller based on the concept of artificial neural networks for a flexible manufacturing system are presented. The recurrent neural network (RNN) type is used for such a purpose. Contrary to the programmable controller, an RNN-based sequential controller is based on a definite mathematical model rather than depending on experience and trial and error techniques. The proposed controller is also more flexible because it is not limited by the restrictions of the finite state automata theory. Adequate guidelines of how to construct an RNN-based sequential controller are presented. These guidelines are applied to different case studies. The proposed controller is tested by simulations and real-time experiments. These tests prove the successfulness of the proposed controller performances. Theoretical as well as experimental results are presented and discussed indicating that the proposed design procedure using Elman's RNN can be effective in designing a sequential controller for event-based type manufacturing systems. In addition, the simulation results assure the effectiveness of the proposed controller to outperform the effect of noisy inputs.     

梯子的模和数

1990年,F．Harary提出了和图的概念,模和图和模和数的概念是由Boland、Sutton等人提出来的．模和图是取S(?)Zm＼{0}且所有算术运算均取模m(≥|S|+1)的和图,其中Zm={0,1,2,…,m-1}．一个图G的模和数ρ(G)是使得G∪ρK1是模和图的孤立点数ρ的最小值．本文证明了kL3(k≥2)是模和图,因而也是模整和图．     

Crown graphs and subdivision of ladders are odd graceful

A graph G of size q is odd graceful, if there is an injection φ from V(G) to {0, 1, 2, …, 2q?1} such that, when each edge xy is assigned the label or weight |f(x)?f(y)|, the resulting edge labels are {1, 3, 5, …, 2q?1}. This definition was introduced in 1991 by Gnanajothi [3], who proved that the graphs obtained by joining a single pendant edge to each vertex of C _n are odd graceful, if n is even. In this paper, we generalize Gnanajothi's result on cycles by showing that the graphs obtained by joining m pendant edges to each vertex of C _n are odd graceful if n is even. We also prove that the subdivision of ladders S(L _n ) (the graphs obtained by subdividing every edge of L _n exactly once) is odd graceful.     

基于西门子S7-300 PLC装卸机械自控系统设计

主要介绍了装卸机械控制系统的构成、系统在运行过程中的控制要求、以及如何实现机械自动操作的功能,利用S7-300PLC的功能模块化程序设计思想,设计出手动控制逻辑功能和自动控制逻辑功能及组织块程序,大大提高了工作效率和生产安全性。     

采用PLC技术完善生产过程监控

介绍了为监控生产过程 ,经过硬件和软件等多方面的改进 ,实现了生产全过程的控制和管理。     

基于多种教学方法优势互补的《C程序设计》课堂教学

该文对C程序设计课堂教学特点进行分析,将课堂教学分为知识引入,详细讲解和内容总结三个阶段,根据各阶段的不同教学目标,将案例教学、阶梯教学、举例教学和传统的讲授教学各方法优势互补地结合起来应用在C程序设计课程课堂教学中。     

PLC在专用镗孔机床控制中的应用

文章介绍了可编程控制（简称PLC）在专用镗孔机床控制中的应用，对系统的硬件和软件作了较为详细的阐述。