Hardware‐oriented ant colony optimization and its application to dynamic route guidance problem

Ant colony optimization (ACO) is based on the behavior of food gathering of ants and it is a powerful search tool particularly when applying it to combinatorial optimization problems. However, ACO has the inherent problem of substantial processing time, because it requires a lot of repetitive calculations. In this article, we propose novel hardware‐oriented ACO (H‐ACO) to reduce processing time. H‐ACO adopts new integer arithmetic instead of conventional floating point arithmetic in the optimization process and it achieves high‐speed processing while keeping the quality of solutions. In addition, H‐ACO reduces the hardware resources, accelerates the clock frequency, and improves the latency, if it is implemented as a dedicated hardware. Furthermore, we also propose a new route guidance algorithm which combines H‐ACO with Dijkstra's algorithm and it can be applied to a dynamic route guidance problem. Experiments using actual map data demonstrate the validity of the proposed route guidance algorithm. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Tribological Properties of Polymer Composites Containing Barite (BaSO4) or Potassium Titanate (K2O · 6(TiO2))

Tribological properties of particulate barite (BaSO₄) and potassium titanate (K₂O·6(TiO₂)) whiskers, the two major ingredients currently used for commercial brake friction materials, were investigated. A novolac resin was used as a binder for test specimens and a block-on-disk tribometer was used to assess friction characteristics of the two ingredients. Experimental results showed that the BaSO₄-filled composite produced large frictional oscillations and created severe damage on the gray iron counter surface, while the composite filled with the same amount of K₂O·6(TiO₂) whiskers showed smooth sliding without large friction force fluctuation. The cause of the different frictional behavior was investigated by considering stick-slip and mechanical properties of the composites, which was largely based on the morphology of the two ingredients and their role in reinforcing the composite. The results from this comparative study suggest that the friction characteristics of commercial friction materials can be strongly affected by the two ingredients, which have been considered as minor constituents for brake performance.     

某雷达微带天线单元制造工艺研究

某雷达微带天线单元结构复杂,其结构板具有开放式、低刚性的薄壁结构,电气板配合面具有局部多层的台阶结构。采用现有制造方法,零件成品率低,存在接地不可靠、驻波损耗大、盲配难等问题。为了解决这些技术问题,从整体工艺路线制定、低温钎焊工艺设计方面,有针对性地提出了有效控制变形、保证板间连接质量的解决方案。检测结果表明,指标满足实际使用要求,性能稳定、可靠,解决了成品率低的问题。该零件已在某机载雷达产品中得到应用。     

考虑实时动态能耗的电动汽车充电路径规划

由于电动汽车在行驶途中电量耗尽的风险较大,亟须研究一种有利于减轻用户出行焦虑的电动汽车充电路径规划方法。文中通过选取能够准确反映实际道路中用户驾驶特性的行驶工况特征参数,分析各特征参数与耗电量之间的相关性以及特征之间的相关性强弱,采用主成分分析对特征进行降维,基于信息熵模糊聚类方法对行驶工况进行分类,构建电动汽车行驶途中的动态能耗模型。并基于此考虑路径选择及电池剩余电量约束,建立以出行总距离、总时间及充电价格三者权值之和最小为目标的电动汽车充电路径规划模型。以某市实际交通路网规划18 km×18 km区域,分析采用实时能耗对充电路径规划的影响以及不同优化目标对用户充电路径优化结果的影响,验证了所提规划方法的可行性及有效性。     

A typical process route discovery method based on clustering analysis

A typical process route is a sample of planning the process route. It is a kind of the process planning knowledge. In order to discover the typical process route in the process planning database from the Computer Aided Process Planning (CAPP), Knowledge Discovery in Database (KDD) is applied. Process data selection, process data purge and process data transformation are employed to get optimized process data. The clustering analysis is adopted as the algorithm mining the typical process route. A mathematics model describing the process route was built by the data matrix. There are three similarities in process route clustering: the similarity between operations was measured by the Manhattan distance based on operation code; the similarity between process routes was calculated by the Euclidean distance and expressed as a dissimilarity matrix; the similarity between process route clusters was evaluated by the average distance based on the dissimilarity matrix. Then, the process route clusters were eventually merged by the agglomerative hierarchical clustering method. And the process routes clustering result was determined by the clustering granularity of process route. This method has been applied successfully to discovering the typical process route of a kind of axle sleeves. This project is supported by the National High-Tech. R&D Program for CIMS, China (Grant No. 2003AA411041).     

分析设计的直接方法

简要介绍欧盟EN13445—3：2002标准中附录B的基本思想。     

船舶在局部区域内自动导航路径识别系统

根据动态路径规划理论和人工智能中知识工程,提出了船舶在局部区域内自动导航的路径识别系统模型及智能控制算法,该算法有效地解决了真实环境下的复杂性和可变性导致系统的不确定性．利用当今航海领域最先进的电子海图技术,在ＷＩＮＤＯＷＳＮＴ平台上,采用面向对象的程序语言ＢＯＲＬＡＮＤＣ＋＋进行了仿真．仿真系统根据环境信息对路径进行动态生成与控制,满足了对真实环境的敏感性要求,为进一步实现船舶的自动导航提供了一些有益的参考．     

间隙引发的变载非线性及其闭环辨识

阐明了齿轮传动位置伺服系统间隙除产生熟知的前向迟滞非线性之外,还将因系统往复运动中加卸载相交替的反向调制致使驱动电机动力学参数同步跳变所出现的变载非线性现象.推导建立了这类非线性在一阶谐波意义下的串联式等效频域模型及其近似计算公式,分析了相应的幅相特性.进一步面向服役中系统提出了直接通过闭环弱自激振荡控制所实现的间隙辨识新方法,给出了控制器的结构及其参数整定策略.此外,文中还给出了含高斯白噪声测量的仿真算例,充分验证了闭环间隙辨识方法的有效性和便捷性.     

E‐TDGO: An encrypted trust‐based dolphin glowworm optimization for secure routing in mobile ad hoc network

Mobile ad hoc networks (MANETs) are independent networks, where mobile nodes communicate with other nodes through wireless links by multihop transmission. Security is still an issue to be fixed in MANETs. Hence, a routing protocol named encrypted trust‐based dolphin glowworm optimization (DGO) (E‐TDGO) is designed using Advanced Encryption Standard‐128 (AES‐128) and trust‐based optimization model for secure routing in MANET. The proposed E‐TDGO protocol includes three phases, namely, k‐path discovery, optimal path selection, and communication. At first, k paths are discovered based on the distance and the trust level of the nodes. From the k paths discovered, the optimal path is selected using a novel algorithm, DGO, which is developed by combining glowworm swarm optimization (GSO) algorithm and dolphin echolocation algorithm (DEA). Once the optimal path is selected, communication begins in the network such that E‐TDGO protocol ensures security. The routing messages are encrypted using AES‐128 with shared code and key to offer security. The experimental results show that the proposed E‐TDGO could attain throughput of 0.11, delay of 0.01 second, packet drop of 0.44, and detection rate of 0.99, at the maximum number of rounds considered in the network of 75 nodes with attack consideration.     

基于阻抗特性多项式拟合的直驱风电机组次同步振荡稳定判据

近年来,阻抗分析法已成为分析新能源发电并网系统稳定性问题的一种主要研究方法。以直驱风电机组并网系统为例,分析了现有的奈奎斯特（Nyquist）稳定判据的特点和适用范围。为了弥补现有阻抗稳定判据的不足,提出了一种基于阻抗特性分式多项式函数拟合的量化稳定判据,采用分式多项式函数等效拟合理论推导或实测的风电机组端口阻抗特性,在拟合频段内分式多项式与原阻抗特性等价。通过求取拟合多项式零点获得了系统振荡频率和阻尼水平,量化分析了系统稳定特性,拓展了阻抗稳定判据的适用范围。最后,通过理论分析和时域仿真验证了分式多项式拟合判据的正确性和有效性。