基于缓冲对刀策略的自动化铲板组件设计

针对目前化纤纺丝生产中对喷丝板进行自动化铲板的需求,首先,提出一种自动铲板方法并设计了具有串并联弹簧缓冲对刀结构的铲板组件;然后,通过规划铲刀组件的对刀运动参数,建立组件的动力学模型,确定缓冲弹簧的刚度系数;同时对铲刀组件的对刀运动进行Adams仿真,验证运动参数设计和串并联弹簧缓冲对刀结构设计的正确性;最后,搭建了自动化铲板实验平台,开展对刀阶段的接触力测量实验。研究结果表明,实际对刀时的受力趋势与仿真结果一致,铲板组件可有效清洁喷丝板面,且随着铲刀接触力的增大铲板效果越明显,该研究为进一步开展自动化铲板系统的设计提供了技术参考。     

基于串联机构的三自由度运动平台设计与仿真分析

以串联机器人为研究对象,设计了一种三自由度串联运动平台,用于汽车驾驶模拟器。运用Inventor建立串联平台的三维模型,导入Adams,获得了平台的虚拟样机。针对汽车主要运行状态进行运动分解,设计虚拟样机的驱动函数模拟汽车运动时的动感,得到了各自由度运动及关键构件的状态参数。分析比较了平台有无减震装置时的性能,对各自由度传动方程进行了验证。提出一种基于Adams和Matlab联合仿真工作空间的新方法,并用该方法绘制了座椅质心的工作空间。获得的仿真数据为后续物理样机的结构设计、运动控制提供了可靠依据。     

Photography and the Elphinstone Institution of Bombay

Abstract

Ralizing the potentials of photography, the Court of Directors of the East India company recommended to the Government of Bombay as early as 1845 ‘the encouragement of the study of this useful art of photography in any of the seientific or educational institutions under the control or inf1uence of your government’. They also offered to furnish students with the requisite apparatus, if they found it necessary to procure them from England¹. The proposal was repeated in their dispatch dated 29th December 1854, when they again expressed their desire to establish training in photography. Thereupon, W. Hart, Secretary to the Government of Bombay, requested the Board of Education of Bombay Presidency to submit a scheme for carrying out this project². Mr Stowell, Secretary to the Board of Education, called for the opinions of the Principal of the Elphinstone Institution, and of its Professor of Chemistry³. A small but interesting episode of early photography in India had its beginning in this way.     

Polaroid,Aperture and Ansel Adams: Rethinking the Industry-Aesthetics Divide

This article takes the history of Polaroid photography as an opportunity to question a presupposition that underpins much thinking on photography: the split between industrial (i.e. useful) applications of photography and its fine art (i.e. aesthetic) manifestations. Critics as ideologically opposed as Peter Bunnell and Abigail Solomon-Godeau steadfastly maintain the existence of this separation of utility and aesthetics in photography, even if they take contrasting views on its meaning and desirability. However, Polaroid, at one time the second largest company in the photo industry, not only enjoyed close relations with those key representatives of fine art photography, Ansel Adams and the magazine Aperture, but it also intermittently asserted the ‘essentially aesthetic’ nature of its commercial and industrial activities in its own internal publications. The divide between industry and aesthetics is untenable, then, but this does not mean that the two poles were reconciled at Polaroid. While Aperture may have underplayed its commercial connections and Polaroid may have retrospectively exaggerated its own contributions to the development of fine art photography, most interesting are the contradictions and tensions that arise when the industrial and the aesthetic come together. The present article draws on original research undertaken at the Polaroid Corporation archives held at the Baker Library, Harvard, as well as with the Ansel Adams correspondence with Polaroid, held at the Polaroid Collections in Concord, Massachusetts.     

平面三自由度机械臂的轨迹规划及仿真

根据D-H坐标变换方法建立平面三自由度机械臂的齐次坐标变换矩阵,用代数方法建立逆运动学方程的数学模型;通过程实现对数学模型的求解,获得机械臂各关节的数据.通过对求解的数据进行处理导入到Adams软件中建模仿真,仿真结果验证数学建模计算数据正确,方法可靠.     

The physical–chemical properties and electrocatalytic performance of iridium oxide in oxygen evolution

An IrO₂ anode catalyst was prepared by using the Adams method for the application of a solid polymer electrolyte (SPE) water electrolyzer. The effect of calcination temperature on the physical–chemical properties and the electrochemical performance of IrO₂ were examined to obtain a low loading and a high catalytic activity of oxygen evolution at the electrode. The physical–chemical properties were studied via thermogravimetry–differential scanning calorimetry (TG–DSC), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical activity was investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry in 0.1 mol L⁻¹ H₂SO₄ at room temperature. The optimum condition was found to be at the calcination temperature of 500 °C, where the total polarization reached a minimum at high current densities (>200 mA cm⁻²). The optimized catalyst was also applied to a membrane electrode assembly (MEA) and stationary current–potential relationships were investigated. With an optimized catalytic IrO₂ loading of 1.5 mg cm⁻² and a 40% Pt/C loading of 0.5 mg cm⁻², the terminal applied potential difference was 1.72 V at 2 A cm⁻² and 80 °C in a SPE water electrolysis cell.     

基于Adams的多连杆机械式压力机动力学分析

针对多连杆机械式压力机,采用模块化方法构建其传动部分数学模型,得到压力机工作机构滑块的运动方程;根据运动方程,利用仿真软件Matlab得出滑块的位移、速度、加速度曲线。用三维软件Soldworks构建传动部分三维模型,应用动力学分析软件Adams对模型进行动力学分析,对比两种结果,得出该结构适用于深拉伸加工工艺,模具在拉伸工作区的冲击很小,满负荷时工作区域长。     

基于Adams的3-(2SPS)并联机构的配重平衡分析

以3-(2SPS)并联机构为研究对象,针对机构动平台质量较大的情况,通过一个二级剪叉机构建立一种配重平衡装置.求出机构位置的正反解,在Adams仿真软件中用纯移动型的3-UPU并联机构等效代替,对配重后的机构进行运动学、动力学以及静力学仿真分析;并通过参数化分析,获得更佳的设计参数.仿真结果表明:优化后,有平衡结构的3...     

Upgrading Computational Design

Shajay Bhooshan heads up the computation and design ZHACODE group at Zaha Hadid Architects (ZHA) and is a course master at the Architectural Association Design Research Laboratory (AADRL). Here he argues that Parametricism 2.0 has a vital role to play in the progressing of computational design. Assimilating the exploratory developments of the last 15 years, he asserts how the next phase of Parametricism will enable a further consolidation and evolution of digital practices.     

The Hinterland Urbanised?

What defines the urban? And can the non-urban necessarily always be classified as rural? Neil Brenner , Director of the Urban Theory Lab at Harvard University Graduate School of Design, reflects on the lack of an overarching theory to describe these realms, and argues that what we call the countryside or the hinterland has become key to the process of capitalist urbanisation.