Predicting configuration performance of modular product family using principal component analysis and support vector machine

A novel configuration performance prediction approach with combination of principal component analysis(PCA) and support vector machine(SVM) was proposed.This method can estimate the performance parameter values of a newly configured product through soft computing technique instead of practical test experiments,which helps to evaluate whether or not the product variant can satisfy the customers' individual requirements.The PCA technique was used to reduce and orthogonalize the module parameters that affect the product performance.Then,these extracted features were used as new input variables in SVM model to mine knowledge from the limited existing product data.The performance values of a newly configured product can be predicted by means of the trained SVM models.This PCA-SVM method can ensure that the performance prediction is executed rapidly and accurately,even under the small sample conditions.The applicability of the proposed method was verified on a family of plate electrostatic precipitators.

Modularity Techniques in High Performance Permanent Magnet Machines and Applications

This paper reviews the modularity techniques in the stator manufacture of permanent magnet machines for different applications.Some basic concepts of modular machines are firstly introduced.Modular machines for several typical applications are then described in details,including domestic appliances,automobiles and electric vehicles,more electric aircrafts and civic applications,wind power generators,etc.Besides,the influence of manufacture tolerance gaps and flux barriers on the electromagnetic performance is discussed.

MODULE DEFINITION MODEL FOR MODULAR DESIGN AND MANUFACTU－RING OF HEAVY DUTY MACHINE TOOLS

The key techniques of modular design of heavy duty NC mathine tools are described. Amodule definition modelfor modular design and manufacturing of heavy duty NC machine tools isbulit and the essential composition of the module definition model (MDM) is discussed in detail. Itis composed of two models: the part definition model (PDM) and the module assembly model(MAM). The PDM and MAM are built and their structures are given. Using object-oriented know-ledge representation and based on these models, an intelligent support system of modular design forheavy duty NC machine tools is developed and implemented This system has been applied to thepractical use of Wuhan Heavy Duty Machine Tool Works

KINEMATIC DESIGN OF A RECONFIGURABLE MINIATURE PARALLEL KINEMATIC MACHINE

The kinematic design of a reconfigurable miniature parallel kinematic machineis dealt with. It shows that the reconfigurability may be realized by packaging a tripod-basedparallel mechanism with fixed length struts into a compact and rigid frame with which the differentconfigurations can be formed. Utilizing a dual parameter model, the influences of the geometricalparameters on the dexterous performance and the workspace/machine volume ratio are investigated. Anovel global performance index for the dimensional synthesis is proposed and optimized, resulting ina set of dimensionless geometrical parameters.

Reliability Analysis of Electrical System of CNC Machine Tool Based on Dynamic Fault Tree Analysis Method

The electrical system of CNC machine tool is very complex which involves many uncertain factors and dynamic stochastic characteristics when failure occurs.Therefore,the traditional system reliability analysis method,fault tree analysis(FTA)method,based on static logic and static failure mechanism is no longer applicable for dynamic systems reliability analysis.Dynamic fault tree(DFT)analysis method can solve this problem effectively.In this method,DFT first should be pretreated to get a simplified fault tree(FT);then the FT was modularized to get the independent static subtrees and dynamic subtrees.Binary decision diagram(BDD)analysis method was used to analyze static subtrees,while an approximation algorithm was used to deal with dynamic subtrees.When the scale of each subtree is smaller than the system scale,the analysis efficiency can be improved significantly.At last,the usefulness of this DFT analysis method was proved by applying it to analyzing the reliability of electrical system.

Overview of Permanent-Magnet Fault-Tolerant Machines: Topology and Design

Permanent-magnet(PM)machines have attracted a lot of interest in various applications since they have the merits of high torque density,high power density and high efficiency.However,issue of poor fault tolerance of the conventional PM machines restricts their practical applications in the field of safety-critical applications,e.g.aerospace,electric vehicle,electrical propulsion and wind power generator applications.An enormous amount of work has been done to improve the fault-tolerant capability of PM machines.This paper will review research work on PM fault-tolerant machines up-to-date,including modular design,short-circuit current limitation design,redundant design,ease of thermal dissipation of PM design,and torque enhancement design techniques.The work of this paper can provide some references for future studies and engineering applications of PM fault-tolerant machines for safety-critical applications.

Recent Development of Reluctance Machines with Different Winding Configurations,Excitation Methods,and Machine Structures

This paper reviews the performances of some newly developed reluctance machines with different winding configurations,excitation methods,stator and rotor structures,and slot/pole number combinations.Both the double layer conventional(DLC-),double layer mutually-coupled(DLMC),single layer conventional(SLC-),and single layer mutually-coupled(SLMC-),as well as fully-pitched(FP)winding configurations have been considered for both rectangular wave and sinewave excitations.Different conduction angles such as unipolar􀫚120°elec.,unipolar/bipolar􀫚180°elec.,bipolar􀫛240°elec.and bipolar􀫜360°elec.have been adopted and the most appropriate conduction angles have been obtained for the SRMs with different winding configurations.In addition,with appropriate conduction angles,the 12-slot/14-pole SRMs with modular stator structure is found to produce similar average torque,but lower torque ripple and iron loss when compared to non-modular 12-slot/8-pole SRMs.With sinewave excitation,the doubly salient synchronous reluctance machines with the DLMC winding can produce the highest average torque at high currents and achieve the highest peak efficiency as well.In order to compare with the conventional synchronous reluctance machines(SynRMs)having flux barriers inside the rotor,the appropriate rotor topologies to obtain the maximum average torque have been investigated for different winding configurations and slot/pole number combinations.Furthermore,some prototypes have been built with different winding configurations,stator structures,and slot/pole combinations to validate the predictions.

RESEARCH ON THE GENERALIZED MODULAR DESIGN METHOD WITH FLEXIBLE MODULES OF PRODUCT STRUCTURES

A new generalized modular design (GMD) method is proposed based on designpractice of frame structure of hydraulic press machines. By building a series of flexible modules(FMs), design knowledge and structure features are integrated into parametric models. Then,parametric design and variational analysis methods for GMD are presented according to user defineddesign objectives and customized product characteristics. A FM-centered GMD system is developed andsuccessfully used in the rapid design of relevant products.

一种提高Modular定子绕组永磁同步发电机感应电动势的新方法

针对Modular定子绕组永磁同步发电机,利用其线圈绕在定子齿上的特点,采用不等槽距的方法,改变线圈正负边的跨度,达到优化永磁同步电机感应电动势幅值目的。仿真结果表明,优化后电机的感应电动势幅值提高了1%,并且保持了模块化,具有齿槽转矩小、谐波含量较小等优点。在保持输出电动势不变的情况下,可以将绕组线圈数目或电机轴向长度减小1%,从而提高电机的材料利用率。

定子间隙宽度对拼块式永磁电机电磁性能的影响

为探究定子间隙宽度对不同槽极配置及不同拼块式结构永磁电机电磁性能的影响,通过有限元仿真软件建立12槽10极和12槽14极定子一体式、E型拼块式、C型拼块式永磁电机的仿真模型,通过改变定子间隙宽度,得出定子间隙宽度与各电磁性能间的关系,并进行理论分析验证。结果表明:12槽10极电机更适合采用C型2 mm/4 mm拼块式结构降低齿槽转矩和转矩脉动;12槽14极电机更适合采用E型4 mm拼块式结构提高输出转矩或采用C型2 mm降低齿槽转矩和转矩脉动。

卧式液压注塑机结构模块化研究与设计

以朗亿LYH680注塑机为例,对其结构和功能进行分析,多角度进行可拆卸评价。将注塑机的总体功能分解成多个功能单元,并从使用者的角度对各单元实施相关性评价,建立相应的相关性矩阵。基于制造、装配与功能3个方面确定各自的权重值,代入总体相关性矩阵;引入截矩阵,以不同阈值为划分标准,实施划分方案比较;依据比较结果及设备实际情况得到功能模块划分方案。通过对注塑机零部件的划分,建立了注塑机模块化设计的方案,增加了注塑机各零部件的通用性,从而有效提升设计、生产效率,促进产品的新技术更新。

造楼机小油缸群组“蜂群式控制”关键技术研究

基于轻量化、模块化、智能化的造楼机设计理念,提出并研发一种小油缸群组“蜂群式控制”造楼机顶升液压驱动系统,该系统由小型高精油缸群组、控制回路和液压动力源组成。深入阐述其技术理论与技术优势,通过分析应用监测数据,表明该系统在轻量化、提升效率及精度、结构适应性与容错率等方面相较国内外同类技术均有明显提高。

浅论模块化技术在高效机房设计中的应用

针对高效机房在三维模型的设计过程中,经常涉及不同应用场景、不同承压标准、不同设备生产商等问题,导致高效机房的设计周期长,标准化难以实现。通过采用模块化设计方法,将高效机房进行模块划分,确定参数化尺寸和系列化结构,实现高效机房三维模型的标准化设计,缩短设计周期。

新能源农机用双永磁游标电机的模型预测电流控制

模块化双永磁游标电机兼具高转矩密度和低铁耗,适用于低速大转矩的直驱应用领域。针对新能源农机用模块化双永磁游标电机控制系统存在的转矩脉动大、电流谐波多和转速波动大等问题,提出一种基于改进式模型预测电流控制策略。相比于传统模型预测电流控制,提出的控制策略采用双矢量模型预测电流控制,在每个控制周期内可同时选择2个任意电压矢量组合作用,扩大了电压矢量的选择和幅值调节范围,可进行更准确的电流控制。同时,考虑系统延迟,在预测控制中加入电流延迟补偿环节。仿真结果表明,所提的控制策略可有效减小转矩脉动、电流谐波和转速波动,提升系统的控制性能。

十叠层模块化高频筛分机的技术研究及工业应用

介绍了十叠层高频筛分机的基本原理、结构特点及主要性能参数,分析了十叠层高频筛分机的技术优势;应用结果表明,十叠层高频筛分机具有物料处理量大、筛分效率高、运行稳定,而且噪声低、维护量小的优势,其应用可带来显著的经济与社会效益。

Quantitative Comparison of Modular Linear Permanent Magnet Vernier Machines with and without Partitioned Primary

A comparison of two modular linear permanent-magnet vernier(LPMV)machines is presented.A modular LPMV machine with a partitioned primary,which can significantly improve the modulation effect,is proposed.Benefitting from the partition design,the space conflict between the permanent magnet(PM)and the armature magnetic field is relieved.First,the topologies of modular LPMV machines with and without a partitioned primary are presented.Then,the effect of the partitioned primary on the modular LPMV machine is analyzed using flux modulation theory.Moreover,analytical expressions for the trapezoidal permeance are derived.In addition,the harmonic components,back electromotive forces,and thrust forces of the machines with and without the partitioned primary are comparatively analyzed.The results reveal that the thrust force density of the LPMV machine with a partitioned primary is increased by 32.3%.Finally,experiments are performed on a prototype machine for validation.

Single-ended Fault Detection Scheme Using Support Vector Machine for Multi-terminal Direct Current Systems Based on Modular Multilevel Converter

This paper proposes a single-ended fault detection scheme for long transmission lines using support vector machine(SVM)for multi-terminal direct current systems based on modular multilevel converter(MMC-MTDC).The scheme overcomes existing detection difficulties in the protection of long transmission lines resulting from high grounding resistance and attenuation,and also avoids the sophisticated process of threshold value selection.The high-frequency components in the measured voltage extracted by a wavelet transform and the amplitude of the zero-mode set of the positive-sequence voltage are the inputs to a trained SVM.The output of the SVM determines the fault type.A model of a four-terminal DC power grid with overhead transmission lines is built in PSCAD/EMTDC.Simulation results of EMTDC confirm that the proposed scheme achieves 100%accuracy in detecting short-circuit faults with high resistance on long transmission lines.The proposed scheme eliminates mal-operation of DC circuit breakers when faced with power order changes or AC-side faults.Its robustness and time delay are also assessed and shown to have no perceptible effect on the speed and accuracy of the detection scheme,thus ensuring its reliability and stability.

模块化机房在金辛达智能化矿井建设中的应用

为达到矿井智能化建设和安全管理的要求,金辛达煤业改造加固矿井信息管理机房,配置模块化的空调系统、服务器机柜支撑系统、动力及环境监控系统、供配电系统和监控主机、视频系统、温湿度监控系统及消防监控系统等综合运维管理平台,以满足矿井智能化、数据化建设需要,实现分区模块化,同时也为矿井安全生产,经营管理提供保障。

FFS一体化包装机电气控制设计与实现

介绍FFS一体化包装机机械结构,结合可编程逻辑控制器(Programmable Logic Controller,PLC)技术进行包装机整体设计,以可靠实用为原则,设计出功能齐全、易于操作的控制系统。设计包装机控制系统后,测试计量及走袋精度。从走袋质量、袋长统计数据来看,该包装机控制系统设计合理,可以保障包装走袋的精度与质量。

飞行器载荷射频综合一体机研究

在复杂电子环境下,飞行器多元作战模式对载荷系统提出了更高的要求。本文依据飞行器综合射频系统载荷的功能需求和应用模式,设计了射频综合一体机,既满足了飞行器对载荷轻量化和低成本的要求,又保证一套硬件平台能够集成所有射频功能。射频综合一体机采用软件化、标准化和模块化设计理念,满足综合射频系统“侦、干、探、通”功能重构和模式切换要求,并且,为了提高产品应用性和降低后勤压力,定义了标准结构、接口和通信协议。对比射频综合一体机和传统射频综合产品,进行效能评估,射频综合一体机在体积、重量、功耗和成本上具有显著优势。