桥式起重机设计验证评审方法研究

首先阐述了设计验证和设计评审的概念以及两者之间的关系,在对我国现行的检验桥式起重机的法律法规分析和研究的基础上,提出了利用计算机辅助设计验证评审的方法,并且介绍了开发出来的桥式起重机计算机辅助设计验证评审软件.软件结合了当前的人工检验方法,参数选取的精炼、操作界面的简捷、验证内容的丰富都充分体现了“辅助”的功能,同时,验证结果也展现出了计算机辅助验证评审方法的良好应用前景.     

Real-time environment design for testing advanced control approaches in parallel robots

Industrialization of parallel robots requires the development of control laws that exploit their capabilities in high performance tasks. Although research in this area is increasing, theoretical results need to be experimentally tested in order to evaluate the proposed solutions. In this paper, implementation requirements of control laws in parallel robotics are discussed, and a design for implementing a real-time control and validation environment is proposed. This design provides three main advantages: (1) is focused on reducing the implementation and validation effort of control laws on prototypes, (2) is defined as an open and modular design, which allows to implement new functionalities, and (3) proposes a hardware abstraction layer which simplifies the implementation of different control laws for a given prototype. The proposed design is validated by its implementation in a five revolute joints parallel robot prototype.     

A simulation-based approach for risk assessment of facility layout designs under stochastic product demands

In traditional facility layout design method, the facility layout is governed by the flow intensity between departments, which is the product flow quantity between departments. A facility layout design must maintain its efficiency over time while coping with the uncertainty in product demand. An error in the product demand assessment can render the layout inefficient with respect to material handling costs. Analytical models for the determination of the risk involved in a facility layout design are difficult to derive when the problem of size and complexity increases. This paper presents a simulation-based method for predicting the uncertainty associated with the layout. The validation of the simulation approach against analytical procedures is first detailed. The methodology for the simulation based approach is provided. Three scenarios of increasing complexity and size are also detailed. Results from case studies have shown that the procedure results in reduction of risk as high as 80%.     

Shape optimization of flow channels based on lattice Boltzmann method

A new optimality criterion algorithm is presented for producing modified shape designs for fluid flow inside channels. To compute the fluid motion in a channel, the lattice Boltzmann method (LBM) was used based on D2Q9 and D3Q15 lattice spaces associated with the Bhatnagar-Gross-Krook (BGK) collision term. An experiential optimality method to design channels with the lowest pressure drop along the passage is introduced. The positions of solid cells and fluid cells are exchanged based on the strain rate tensor at the solid-fluid interface. To obtain the optimized shape, the cells are changed until the optimality condition is obtained with the restriction of constant fluid volume. Examples are presented to validate the algorithm, including an elbow tube as well as symmetrical and nonsymmetrical Tjunction channels. The validation exercises demonstrate that the algorithm is suitable for optimal channel design.     

某车型前排座椅行李箱冲击仿真分析和实验验证

以某车型前排座椅为例,介绍一种前排座椅行李箱碰撞设计要求;详细说明如何使用有限元仿真分析方法来辅助产品设计,和在仿真分析中需要重点关注的几个位置。仿真结果证明:所设计的前排座椅骨架性能优秀;并且座椅产品通过了试验验证,符合法规要求。     

弹性连杆机构结构和噪声控制一体化设计

对基于噪声控制的弹性连杆机构结构控制同步优化问题进行了讨论,以机构杆件的厚度和控制系统参数同时作为设计变量,以结构质量和受控系统能量量度的加权和作为性能函数,利用改进的约束变尺度法进行了优化分析。通过算例说明了该法的有效性。     

Train Vehicle Structure Design from the Perspective of Evacuation

The safety of trains,a highly efficient mode of transportation,has attracted significant attention.In the vehicle structure design of a train,the evaluation of the passenger evacuation time is necessary.The establishment of a simulation model is the fastest,most convenient,and practical way to achieve this goal.However,few scholars have focused on the reliability of a passenger train evacuation simulation model.This paper proposes a new validation method based on dynamic time warping and multidimensional scaling.The proposed method validates the dynamic process of a simulation model,provides statistical results,and can be used for small-sample scenarios such as a train evacuation scenario.The results of a case study indicate that the proposed method is an effective and quantitative approach to the validation of simulation models in a dynamic process.Thus,this paper describes the influence of the train structure size on an evacuation based on the results of simulation experiments.The structural size factors include the door width,aisle width,and seat pitch.The experiment results indicate that a wide aisle and reasonable seat pitch can promote a proper evacuation.In addition,a normal train door width has no effect on an evacuation.     

基于近红外波长组合快速检测油页岩含油率

为实现油页岩含油率的快速单点测量,研究了基于近红外波长组合的油页岩含油率快速检测方法。以高岭土与机油混合的模拟样品为研究对象,利用便携式近红外光谱分析技术,研究了近红外波长组合选择方法。该方法采用自制的便携式光谱仪获得全光谱反射率数据,结合微分和多元散射校正数据处理及相关系数法进行波长初步筛选,将组合生成算法与留一交互校验多元线性回归(MLR)建模相结合,确定最佳波长组合,并用MLR建模对单点测量获得的最佳波长组合光谱数据进行了实验验证。结果表明:最佳波长组合为1 644,1 720,2 210,2 260nm,30个建模样品的校正集和预测集的决定系数为0.995 4和0.997 7,11个验证样品的验证集的决定系数为0.990 1。该方法为研制基于单点测量的油页岩含油率快速检测光谱仪提供了基础。     

ADAPTIVE VARIABLE STRUCTURE CONTROLLERS AND APPLICATION TO ENGINE IDLE SPEED CONTROL SIMULATION

A neural-network-based adaptive variable structure control methodology is proposed for the tracking problem of nonlinear discrete-time input-output systems. The unknown dynamics of the system are approximated via radial basis function neural networks. The control law is based on sliding modes and simple to implement. The discrete-time adaptive law for tuning the weight of neural networks is presented using the adaptive filtering algorithm with residue upper-bound compensation. The application of the proposed controller to engine idle speed control design is discussed. The results indicate the validation and effectiveness of this approach.     

基于WEB的三维可视化实时协同设计系统研究与应用

建立了一个基于WEB的实时协同设计系统。在分析协同设计当前面临的主要问题的基础上,提出了适应当前网络条件和紧密型企业集团协同需求的解决方案,实现本地企业基于全特征参数CAD模型的协同交互,以及异地企业基于VRML模型的混合协同交互。在分析了C/S和B/S模式各自特点的基础上,提出了C-B/S混合模式的应用。描述了系统功能,给出了系统的物理体系结构,介绍了系统实现过程中用到的关键技术,并通过一个应用实例进行了验证。     

A Fast Interference Checking Algorithm for Automated Fixture Design Verification

Fixtures are tooling devices used to locate, support and hold workpieces during a manufacturing process. The major purpose of a computer-aided fixture design (CAFD) system is to provide a fixture design based on fixturing principles and workpiece information. Interference checking between the machining tool and fixture units, as well as between fixture units, is one of the important functions of automated fixture design. This paper presents a fast interference checking algorithm for automated modular fixture design validation. It is based on the study of the geometric characteristics of modular fixture components and the machining tool. The fixture component model is simplified into a 2D contour model with height information. The tool-path model is represented by a moving dot for 3-axis operations, or a moving line segment in 5-axis operations, as the fixture component model is different from the popular collision detection procedure using swept volume and is more efficient for fixturing verification. Application of this method will greatly reduce the computation complexity for fixturing interference checking. The method is implemented with a CAFD system. An example is given at the end of the paper.     

外露式星载光机电设备热设计的间接验证

星载光机电设备兼有光学系统和运动机构的特点,前者温度指标要求高,后者构型复杂并且相对星体其他部分运动,这给热设计的验证带来困难。文章以光机电设备激光通信终端为例,提出了热设计的间接验证方法,即通过地面试验数据修正热分析模型、再由热分析模型预示在轨温度,进而验证热设计。设计了热平衡试验,并根据试验结果修正了模型,修正后的试验模型计算结果与试验结果基本一致,81%的测温点偏差小于5℃,模型较好地反映了真实的热物理状态,其预示的在轨温度可用于验证热设计。对比了轨道计算温度与飞行温度,81%的测温点偏差小于4℃,证明了间接验证方法的正确和有效,满足星载激光通信终端的应用要求。所述的验证方法显著降低了热试验的难度,对多姿态与高温度指标的光机电设备具有借鉴意义。     

机电BIT系统中基于因果网络模型的传感器证实算法研究

随着对诊断决策要求的提高,传感器证实已经逐渐成为机电设计状态检测和诊断系统中不可忽视的技术。通过对研究方法的调研和总结,考虑到在BIT系统中应用的特点及需求,研究采用基于知识模型冗余的传感器证实技术以实现更好的实时性。研究了基于传感器因果网络模型的传感器证实算法,实现对网络中节点和链接间相关信息的融合,以得到准确的证实结果,并在实例应用中验证了方法的有效性。     

Multi-objective optimum design of fast tool servo based on improved differential evolution algorithm

The flexure-based mechanism is a promising realization of fast tool servo (FTS), and the optimum determination of flexure hinge parameters is one of the most important elements in the FTS design. This paper presents a multi-objective optimization approach to optimizing the dimension and position parameters of the flexure-based mechanism, which is based on the improved differential evolution algorithm embedding chaos and nonlinear simulated anneal algorithm. The results of optimum design show that the proposed algorithm has excellent performance and a well-balanced compromise is made between two conflicting objectives, the stroke and natural frequency of the FTS mechanism. The validation tests based on finite element analysis (FEA) show good agreement with the results obtained by using the proposed theoretical algorithm of this paper. Finally, a series of experimental tests are conducted to validate the design process and assess the performance of the FTS mechanism. The designed FTS reaches up to a stroke of 10.25 μm with at least 2 kHz bandwidth. Both of the FEA and experimental results demonstrate that the parameters of the flexure-based mechanism determined by the proposed approaches can achieve the specified performance and the proposed approach is suitable for the optimum design of FTS mechanism and of excellent performances.     

领域知识获取与有效性检查过程集成研究

建立适合复杂产品设计领域特点的层次化领域知识表示模型 ,研究领域知识的有效性检查过程 ,并将领域知识的获取过程与领域知识的有效性检查过程有机集成起来 ,在领域知识获取的过程中实现领域知识的一致性、完整性检查 ,在此基础上开发多级领域知识获取系统 MKAS     

电子设计自动化工具集成与异构数据接口

针对国内电子设计自动化工具配置和使用现状，选择了最具代表性的三种电子设计自动化工具：Windows平台的Protel、Unix平台的Cadence 、Me ntor，开发了它们之间不同层次的数据转换接口，沟通了这几种典型的电子设计自动化工具，在此基础上采用客户机／服务器模式，构建了一个并行的产品数据管理体系和设计环境，为分散设计、集中制造提供方便，实现了异地设计、异地验证和集中制造。     

数字规划验证体系研究与应用

从介绍数字化产品开发技术及实施方法入手,研究了面向装配的设计、数字工艺生产规划与验证的理论方法和技术实现,提出了数字化产品开发与规划验证的体系结构,说明了规划验证过程和评价方法。基于并行工程的数字规划与验证方法能够促进工艺和生产规划,在早期确保产品的可制造性、可生产性和产品设计质量。最后。实现了汽车驾驶舱的数字装配仿真与工艺生产规划验证过程。     

基于CAD二次开发实现插齿加工三维动态仿真

利用VB语言,通过二次开发技术在AutoCAD中进行插齿刀三维建模及动态插齿加工过程。直观地体现了齿轮的三维精确成型过程,并对齿轮齿厚、渐开线起始圆、齿顶、齿底及过渡曲线等进行测量,作为插齿刀设计、代用、验证的依据。     

基于ANSYS的压力容器多变量优化设计

在传统的压力容器设计中,一般使用相关的计算公式进行设计,准确性不高,安全系数过大,经济性较差。产品验证依赖于对实物样品的测试,使产品开发周期长,成本高。将压力容器的初步设计、三维软件参数化建模与有限元分析相结合,给出在UG环境下,进行优化设计的方法与过程,并给出了煤气压力容器优化应用实例。     

基于Hypermesh门式起重机优化主梁可行性仿真分析

针对某门式起重机主梁进行拓扑优化设计,得到主梁腹板材料分布的整体方案,并根据新方案详细设计了门式起重机主梁结构。然后对优化后的主梁结构进行了虚拟试验,分析表明基于拓扑优化设计的门式起重机主梁满足刚度和强度的设计要求。采用虚拟试验的研究方法,验证了优化设计方案的可行性,为门式起重机主梁的结构设计提供了一个高效的验证途径。