50MN压平机新型升降平台运动学分析

针对传统升降平台易发生平台倾斜、稳定性差等现象,设计了一种新型的平稳性较高的升降机构。为了确保这种结构能达到设计要求,采用ADAMS软件对其进行运动仿真,得出液压缸的推力曲线轨迹和上台板质心的位置曲线轨迹。通过上述分析确定了新型升降平台的设计方案,也为类似装置的设计提供了帮助。     

Mathew & Ghosh Architects

The work of Mathew & Ghosh Architects (Nisha Mathew-Ghosh and Soumitro Ghosh) boldly extends an abstract Modernist language and at the same time draws from the vitality of places. While the firm's early works were small in scale, mostly residential in nature and based on a reappraisal of the early Corbusian idiom, recent projects include large-scale urban and landscape interventions with diverse conceptual and metaphorical imperatives. They have moved from a more reticent stance to the urban exuberance of their more recent projects (for example, their own office building), something akin to a ‘savage architecture’ as posited by Kazuo Shinohara in the context of the unsynchronised nature of the modern city. The architects' object of contemplation is the urban ‘box’, whether a private residence, office or part of a church. The box is first fractured and reconstructed as a bricolage of tectonic fragments, memories and events, all tenuously related as if unity in a contemporary culture is for ever denied. Like the Japanese notion of ‘ma’, the moment between fragments - a slit or an emptiness between two hovering planes - is telling. Mathew & Ghosh participate in the continuity of a historical narrative yet mark out the fissures and disjunctions; sometimes negotiations with the continuity emerge from unintended interstices. While these configurations of the contemporary urban ‘box’ are both contextual and abstract, they are also phenomenologically rich. There is a sustained dialect to the architecture of Mathew & Ghosh that includes consummate materiality and fine crafting, light as a medium, and always, as Nisha Mathew-Ghosh states, ‘good spatial possibilities’. Copyright © 2007 John Wiley & Sons, Ltd.     

物流仓库取送货工业机器人教学设备设计

介绍物流仓库取送货工业机器人教学设备的总体方案、结构设计及液压传动设计等内容 ,为实训教学提供条件 ,给学生创新思维创造良好的环境 ,培养学生正确设计PLC控制系统和液压传动系统的调整、故障排除等技能。     

前视阵高速雷达空时处理方法研究

多普勒严重模糊,训练样本有限是高速平台雷达面临的重要问题,协方差矩阵估计误差以及目标约束误差将使处理器性能严重下降。针对上述问题,该文对前视阵杂波自由度进行了研究,分析表明杂波特征谱与孔径带宽积、时宽带宽积以及空时耦合特性有关。该文提出基于主瓣区域空时多波束的鲁棒空时处理方法,首先通过空时多波束降低杂波自由度,然后利用多普勒区间约束的方法,提高了处理器的性能和系统鲁棒性。仿真实验证明了该文方法的有效性,当样本中存在目标信号时,该文方法相比传统固定约束矢量的方法输出信杂噪比性能平均提高5 dB左右。     

基于Linux平台的电子商务网站的研究与开发

该文介绍了利用Linux作为平台,以PHP语言作为编程语言和以MYSQL作为网络数据库来组建电子商务网站的方法,它们都是免费开放的源代码或自由软件。文章还详细介绍了一个具体的网上书店的功能实现。     

Analysis of robust stability and performance for two-degree of freedom control structure with dynamic controller

In the two-degree of freedom control, the performance of good command following and disturbance rejection are considered separately. Qualitatively, good performance is equivalent to minimizing the energy of the error for any inputs. In this work, usingH _∞-formulation in the frequency domain, robust stability and robust performance specifications have been analyzed for the two-degree of freedom control structure with a dynamic controller. When the two-degree of freedom system having a feed-forward loop is controlled by a dynamic controller, two different performance weight functions are imposed and the robust performance specification is proposed in terms of the return ratio and feed-forward loop. The design algorithm in the frequency domain is illustrated for the simplified retail model of Industrial Dynamics to compare three kinds of control laws, which are the output feedback control scheme and two additional dynamic control ones. Numerical simulation results show that the dynamic control laws provide a larger robust stability margin than the output feeback control one and has good performance robustness for disturbance rejection at low frequencies.     

基于夹具设计中定位销长度的分析

分析了机床夹具设计中，使用圆柱销作为定位元件时，定位销的定位作用及定位销临界尺寸的界定；论述了采用定位销定位时，定位销长度的设计选择对工件加工定位的影响。无论欠定位或过定位均会对夹具的定位精度产生影响，从而影响到工件的加工质量。     

基于特征的几何公差实体模型的研究(二)—— CAD/CAAM 中基于 GTSB 表示的基准坐标及公差约束拓扑图

本文利用基于特征的ＧＴＳＢ（ＧｅｏｍｅｔｒｉｃＴｏｌｅｒ－ａｎｃｅＳｔｒｕｃｔｕｒｅＢｌｏｃｋｓ简称ＧＴＳＢ）不仅建立了参考基准坐标系，并且成功地表示了３Ｄ几何公差对机械零件的约束关系。其公差约束拓扑图（ＴｏｌｅｒａｎｃｅＣｏｎｓｔｒａｉｎｔＴｏｐｏｌｏｇｙＧｒａｐｈ）逻辑推理简单方便，表示直观、清楚，且实现了参数化表示。ＴＣＴＧ它是基于Ｂ－ｒｅｐ和ＣＳＧ表示的公差实体模型的不可缺少的一个部分。     

云天化集团总部办公楼、科技楼

本文以自主设计为主线,结合云天化集团总部办公楼及科技楼的设计实践,着重从总体布局、建筑造型、建筑空间等几个方面,阐述建筑师的设计理念以及自主设计的积极意义。业主对建筑师的信任是自主设计的前提条件,更宽松的创作环境,更自由的创作空间,将更能激发建筑师的创作热情和创作潜能,从而设计出更多的优秀建筑作品。     

A Novel Hybrid Salp Swarm Differential Evolution Algorithm Based 2DOF Tilted-Integral-Derivative Controller for Restructured AGC

Abstract

This article elevates the study of Automatic Generation Control (AGC) for a multisource interconnected power system under the restructured environment. Physical constraints such as Generation Rate Constraints (GRC), Governor Dead Band (GDB) and Boiler Dynamics (BD) are incorporated into the system for a more realistic approach. Distribution Generation (DG) system is also considered to incorporate the effects of renewable energy sources penetration. A novel cascaded topology of 2-Degree of Freedom Tilted-Integral-Derivative Controller with filter (2DOF-TIDN) is proposed for anticipated AGC mechanism. A maiden application of Hybrid Salp Swarm Differential Evolution Algorithm (HSSDEA) has been successfully applied to get the different optimum gains of the proposed controller. Capacitive Energy Storage (CES) system is also incorporated for the proposed system for the AGC mechanism. The supremacy of the proposed controller is examined by comparing with other well-known or benchmark controllers. The robustness of the proposed system has been analyzed for the contract violation case of deregulation. Finally, the efficacy of the proposed work has been verified by comparing with the previously published work of literature on same platform.