Application of the PSO–SVM model for recognition of control chart patterns

Control chart patterns are important statistical process control tools for determining whether a process is run in its intended mode or in the presence of unnatural patterns. Accurate recognition of control chart patterns is essential for efficient system monitoring to maintain high-quality products. This paper introduces a novel hybrid intelligent system that includes three main modules: a feature extraction module, a classifier module, and an optimization module. In the feature extraction module, a proper set combining the shape features and statistical features is proposed as the efficient characteristic of the patterns. In the classifier module, a multi-class support vector machine (SVM)-based classifier is proposed. For the optimization module, a particle swarm optimization algorithm is proposed to improve the generalization performance of the recognizer. In this module, it the SVM classifier design is optimized by searching for the best value of the parameters that tune its discriminant function (kernel parameter selection) and upstream by looking for the best subset of features that feed the classifier. Simulation results show that the proposed algorithm has very high recognition accuracy. This high efficiency is achieved with only little features, which have been selected using particle swarm optimizer.     

垂直流人工湿地内水流流态分析

通过示踪剂实验,采用停留时间分布(RTD)理论对不同出水口高度下垂直流人工湿地内的水流流态进行了分析。研究表明水流在垂直流人工湿地中的流动是介于理想的活塞流和全混流之间的非理想流动状态;不同出水口高度下,垂直流人工湿地内水流流态的不同主要体现在水流在人工湿地内停留时间的长短上面,而水流的分散程度相差不大;出水口较高时,水流在垂直流人工湿地内的平均停留时间也较长,该水流流态有利于污染物在人工湿地中的降解。     

Electric field controlled electrospray deposition for precise particle pattern and cell pattern formation

Photolithography, soft lithography, and ink jetting have been used for automated micropattern fabrication. However, most of the methods for microfabrication of surface pattern are limited to the investigation of material properties of substrates with high‐cost and complex procedures. In the present study, we show a simple (single‐step) yet versatile and robust approach to generate biodegradable polymeric particle patterns on a substrate using electrospray deposition through a mask. Various particle patterns including patterned dots, circles, squares, and bands can be easily formed and the features of particle patterns could also be tailored using different masks and electrostatic focusing effects. Furthermore, cell patterns can be achieved on the surface of particle patterns by blocking the areas without particle deposition on the substrate and culturing cells on the substrate. Polymeric particle patterns and cell patterns developed in this study could be used in the high throughput screening of sustained release formulations, cell‐based sensing, and drug discovery. In addition to experimental results, an analysis of the associated electric field is used to investigate quantitatively the nature of focusing effect. Scaling analysis is also applied to obtain the dominate terms in electrospray deposition process. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

不等开口压力容器非测地线缠绕的CAD/CAM技术

本文针对两端封头开口比大的复合材料容器在缠绕工艺中遇到的纤维滑线问题,对圆筒段路径采用非测地线,封头为近测地线的轨迹,详细讨论了不同结构形式容器缠绕角的求解方法,从而实现非测地线路径设计.并给出非测地线稳定缠绕的判别公式,对缠绕可行性进行了分析判断.最后在此基础上开发了缠绕程序,实现了缠绕工艺的自动化铺层设计和缠绕成型,对不等开口容器的缠绕设计和工艺具有指导性作用.     

一种数控力/位置控制半实物仿真系统的构建

针对数控系统的力位置控制实现难度大、参数调整复杂的问题,研究了一种基于Quanser Q8卡和Si mulink的半实物仿真系统。以X-Y-Z三轴运动平台为对象,对该系统中软硬件的具体构成进行了设计。通过以Z轴的恒接触力控制为目标,在Si mulink软件中设计了含有位置环和力环的控制器,给出了实际仿真曲线。结果表明,该系统控制器设计合理,参数调整简单,控制效果观察直观。     

6自由度3-PRPS并联机器人运动规划分析及仿真

6自由度3-PRRS机构是基于Stewart平台设计出来的一种特殊构型的新型并联机构。为了准确分析该机构运动学特性并从运动规划角度研究机构关键参数与机构运动的关系,建立了有效的运动学模型对机构进行分析,给出了位置反解,同时面向工程应用提出了运动规划,然后利用ADAMS软件进行仿真分析。其中建立了不同平台尺寸比率k的模型,对动平台施加运动来观察、研究比率k的变化对连杆运动产生的影响,给出了3-PRRS机构关键参数比率k与机构运动的关系。分析结果为该类型机构位置反解研究提供了可行路径,避免了大量的数学计算和编程工作,提高了工作效率;并有助于在3-PRRS机构设计中,针对不同应用场景合理选择不同的参数模型。     

基于PLC控制的温度控制器测试系统的设计

针对家用和类似用途温度控制器类产品,以相关的国际和国家标准为研究依据,着眼于节约试验用能源、提高试验精度和检测效率,结合制冷系统原理、运动控制技术和电工电子技术,采用冷风半闭式循环和强制对流热交换方式等策略,实现了节能型可编程温度控制器测试系统的研制与开发。     

虚拟人动作编辑器关键技术研究

针对现有虚拟人运动生成技术的不足,采用关键帧技术,捅值算法,三维空间中模型的拾取算法,开发出虚拟人动作编辑器系统。该系统可实现虚拟人在虚拟环境中各种动作仿真,现已成功应用于某城市列车驾驶模拟仿真器的视景仿真系统。     

刚体—微梁系统的动力学特性

由于微尺度领域材料的力学性能存在尺度效应,使得微梁的动力学性态较传统的大尺寸柔性梁的动力学性态呈现明显的不同。对中心转动刚体、柔性微梁组成的刚体—微梁一类刚柔耦合系统的动力学特性进行研究。在柔性微梁变形位移中,计及横向位移引起轴向缩短的耦合变形量,采用偶应力理论(又称Cosserat理论)研究微梁动力学特性的尺度效应,由Hamilton原理推导出系统考虑尺度效应的刚柔耦合动力学方程。在此基础上,分析微梁固有频率对微尺度的依赖性,比较在不同转速下零次近似模型和一次近似模型振动频率的差异,从而确定在考虑尺度效应的微尺度下零次近似模型的适用范围,最后分析尺度效应和耦合变形量对微梁刚度的影响。研究表明,尺度效应提高微梁的固有频率,尺度效应对微梁刚度的影响是静态的,耦合变形量对微梁的刚度的影响与转速有关。     

陶瓷零件快速成型机数控系统开发

在IPC+运动控制器的开放式数控平台上,结合陶瓷零件快速成型工艺加工过程,构建了硬件系统和软件系统,并进行功能模块的划分以及具体方法的实现,利用VC++语言,设计开发出针对陶瓷模具加工的开放式陶瓷快速成型数控系统.