Engineering knowledge formalization and proposition for informatics development towards a CAD-integrated DfX system for product design

Target design methodologies (DfX) were developed to cope with specific engineering design issues such as cost-effectiveness, manufacturability, assemblability, maintainability, among others. However, DfX methodologies are undergoing the lack of real integration with 3D CAD systems. Their principles are currently applied downstream of the 3D modelling by following the well-known rules available from the literature and engineers’ know-how (tacit internal knowledge).This paper provides a method to formalize complex DfX engineering knowledge into explicit knowledge that can be reused for Advanced Engineering Informatics to aid designers and engineers in developing mechanical products. This research work wants to define a general method (ontology) able to couple DfX design guidelines (engineering knowledge) with geometrical product features of a product 3D model (engineering parametric data). A common layer for all DfX methods (horizontal) and dedicated layers for each DfX method (vertical) allow creating the suitable ontology for the systematic collection of the DfX rules considering each target. Moreover, the proposed framework is the first step for developing (future work) a software tool to assist engineers and designers during product development (3D CAD modelling).A design for assembly (DfA) case study shows how to collect assembly rules in the given framework. It demonstrates the applicability of the CAD-integrated DfX system in the mechanical design of a jig-crane. Several benefits are recognized: (i) systematic collection of DfA rules for informatics development, (ii) identification of assembly issues in the product development process, and (iii) reduction of effort and time during the design review.     

Reliability-based design optimization of knuckle component using conservative method of moving least squares meta-models

This paper discusses reliability-based design optimization (RBDO) of an automotive knuckle component under bump and brake loading conditions. The probabilistic design problem is to minimize the weight of a knuckle component subject to stresses, deformations, and frequency constraints in order to meet the given target reliability. The initial design is generated based on an actual vehicle specification. The finite element analysis is conducted using ABAQUS, and the probabilistic optimal solutions are obtained via the moving least squares method (MLSM) in the context of approximate optimization. For the meta-modeling of inequality constraint functions, a constraint-feasible moving least squares method (CF-MLSM) is used in the present study. The method of CF-MLSM based RBDO has been shown to not only ensure constraint feasibility in a case where the meta-model-based RBDO process is employed, but also to require low expense, as compared with both conventional MLSM and non-approximate RBDO methods.     

基于“OBE+思政”理念的电力电子实验教学改革

以“成果导向教育+课程思政”两大理念为核心,对电力电子实验进行改革,构建蕴含思政的课程预期学习成果,改革教学内容,深入挖掘思政元素,使得育人与育才相统一;实施基于学生能力培养的多元化的教学模式,使知识传授与价值引领相统一;采用多元化的评价方式,科学合理的对学生进行评价,实现“价值塑造、情感激励、能力培养、知识传授”四位一体的教学目标。     

基于边缘差异的虚拟视图像质量评价方法

为了降低多视视频中的传输数据量,可适当减少包含纹理图及其对应深度图的多视数量,而在自由立体视频系统的终端采用基于深度图的绘制技术,生成新的虚拟视点。由于不准确的深度图估计、遮挡及合成算法等原因,合成虚拟视的边缘会出现高频噪声。对于这种特有的失真,用一般的评价方法并不能准确反映人眼的视觉感知。该文在分析失真虚拟视与原始视像素差异基础上,对各差异像素进行分类,并分配权重,提出了一种基于视觉加权的边缘差异质量评价方法,对边缘像素施加较高权重。经多视视频序列实验证明,该文方法相比于其它评价方法,能更好地预测人类视觉对虚拟视图像的主观感知。     

基于UG的注塑模标准模架设计

ＢＡＳＥＣＡＤ系统数据库和程序参数化技术结合起来，利用人工智能的方法，基于ＵＧ的二次开发语言ＧＲＩＰ和Ｃ语言混合编程，在工程工作站开发而成，利用此系统主塑模模架直以观，形象具有选型迅速，设计正确的特点。     

美国星基增强系统发展现状和未来

本文介绍了星基增强系统产生的背景以及美国的星基增强系统WAAS（广域增强系统）的系统架构,回顾了WAAS（广域增强系统）的发展历史,分析了WAAS（广域增强系统）的发展现状和未来的发展方向。     

PROFINET CBA组件的应用实现

PROFINET是基于工业以太网的开放标准,PROFINET基于组件的自动化（CBA）技术通过采用标准自动化组件实现了分布式自动化系统简单高效的互联。本文研究了PROFINET CBA的通信原理、模型,基于PI组织的PROFINET CBA Runtime Source代码开发了PROFINET CBA自动化组件,实现了PROFINET CBA组件之间的实时通信,对于构建基于PROFINET CBA的分布式通信系统具有一定的工程意义。     

从单幅灰度图像中求解三维物体姿态的方法

诸如车辆之类的三维物体的运动常常被约束于一个平面上.这种平面约束显著减少二维图像到三维目标的匹配自由度,从而使得这类三维目标的识别问题得到极大简化.基于此,本文提出一种从单幅定标的灰度图像中求解约束于一已知平面的三维目标的方法.该方法首先计算出给定模型所有可能的旋转角度,再通过聚类获得一些可能的旋转角度类.在每个角度类中,我们对目标所有可能的位置进行计算,并通过聚类获得在此旋转角度下的位置类.之后将候选的角度和位置进行过滤并进行优化以获得最终结果.该算法对于三维目标的部分遮挡具有较好的适应性,其有效性得到实验验证.     

Interactive Cuts through 3-Dimensional Soft Tissue

We describe a physically based framework for interactive modeling and cutting of 3-dimensional soft tissue that can be used for surgery simulation. Unlike existing approaches which are mostly designed for tensorproduct grids our methods operate on tetrahedral decompositions giving more topological and geometric flexibility for the efficient modeling of complex anatomical structures. We start from an initial tetrahedralization such as being provided by any conventional meshing method. In order to track topological changes tetrahedra intersected by the virtual scalpel are split into substructures whose connectivity follows the trajectory of the cut, which can be arbitrary. For the efficient computation of collisions between the scalpel and individual tetrahedra we devised a local collision detection algorithm. The underlying physics is approximated through masses and springs attached to each tetrahedral vertex and edge. A hierarchical Runge-Kutta iteration computes the relaxation of the system by traversing the designed data structures in a breadth-first order. The framework includes a force-feedback interface and uses real-time texture mapping to enhance the visual realism.     

基于单片机控制的电话授时系统及实验数据分析

本文介绍了以ＡＴ８９Ｃ２０５１单片机为主的电话授时系统工作过程、测试原理、误差分析和数据处理。并给出了统计分析结果。