机床故障诊断系统知识表示的研究

针对所研究的机床故障诊断专家系统，以故障树分析法为基础，采用面向对象的事件知识表示方法。并以面向对象编程技术给出了知识表示的示例。分析了这种知识表示方法的特点。实践证明，这种知识表示方法在故障诊断专家系统中是确实有效的，而且这种表示方法融合了多种传统知识表示方法的长处，是一种值得研究与应用的方法。     

灰色系统建模理论在机床主轴疲劳寿命设计中的应用研究

运用灰色系统的理论及方法，将疲劳应力与寿命的相互制约关系看成一个灰色系统，将疲劳试验的应力水平均匀分成数级，并找出与之对应的安全寿命的白化值。通过对安全寿命值数列的一次累加，生成一个光滑离散函数。据此建立灰色系统模型，并求解灰色系统的微分方程 。通过残差模型的修正，提高模型精度，再运用灰色系统模型的还原模型，可计算出任一应力水平下的安全寿命值。为机床主轴的安全寿命计算提供了新的途径，具有较大的推广应用价值。     

机床圆柱结合部的动态特性解析方法

在机床图纸设计阶段，预测机床整机的动态特性具有十分重要的意义，进行机床整机动态特性预测的难点在于如何确定结合部的刚度和阻尼参数，本文以机床结构中应用较普遍的圆柱结合部为例，研究了基于结合面基础特性参数的圆柱结合部动态特性解析方法，并编制相应解析软件，给出应用实例，证明本文的方法及软件是正确的。     

机床电力拖动脉冲宽度调制技术的研究

本文重点介绍用于机床电力拖动系统中的电机脉冲调制(PWM)技术，在分析现有脉冲宽度调制技术的基础上，提出一种采用优化技术生成PWM调制波的方法，推导了优化PWM调制波的求解过程，给出了其计算公式。     

有限状态机在数控系统软件中的应用研究

在数控系统软件开发中，控制软件的开发是开发的关键。针对数控系统复杂性和实时性特点，把有限状态机应用在数控系统软件开发中，构造了控制器软件结构，并应用于数控系统的原型开发。     

压铸件全自动生产系统的设计与控制

为了满足国际客户对压铸件批量、品质及压铸工艺统计过程控制的要求,使用工业机器人替代程控压铸机取件、喷淋、吹干机械手;增设剪口模用液压机;机器人控制压铸机、液压机及压铸循环,实现压铸件全自动生产。概述了压铸件全自动生产系统的设计和控制方法,并指出了自动压铸工艺的局限性。     

Advanced experimental and numerical methods for the analysis of the dynamic forming press behavior

Numerical simulations are used to estimate the dynamic behavior of new concepts of forming presses as well as to improve the dynamic properties of existing machines. These simulations are to be parametrized with appropriate values in order to yield most accurate results. In many cases neither the way of building up the simulation model for the specific problem nor an appropriate method for gathering the needed date are given in advance. Regarding these facts this paper intends both to characterize the way of building up complex simulation models by using basic simulation modules and to describe methods for the identification of the needed parameters that work even under conditions that hitherto made parameter identifications impossible or at least very time-consuming. In this context recent developments in simulating press dynamics will also be characterized as new modal analysis methods that are not yet established in the field of forming technique. The research activities were financed by the European Research Association for Sheet Metal Working.     

Quadratic optimization fine tuning for the Support Vector Machines learning phase

This work presents a comparative analysis of specific, rather than general, mathematical programming implementation techniques of the quadratic optimization problem (QP) based on Support Vector Machines (SVM) learning process. Considering the Karush–Kuhn–Tucker (KKT) optimality conditions, we present a strategy of implementation of the SVM-QP following three classical approaches: (i) active set, also divided in primal and dual spaces, methods, (ii) interior point methods and (iii) linearization strategies. We also present the general extension to treat large-scale applications consisting in a general decomposition of the QP problem into smaller ones, conserving the exact solution approach. In the same manner, we propose a set of heuristics to take into account for a better than a random selection process for the initialization of the decomposition strategy. We compare the performances of the optimization strategies using some well-known benchmark databases.     

Raw data extraction from electrocardiograms with Portable Document Format

During the last two decades there has been a thorough research and development of standards and protocols in order to cope with different electrocardiogram formats from heterogeneous acquisition systems. Despite the efforts of public and private consortiums on creating a standardized electrocardiogram (ECG) storage format, there is still not a single one. Indeed, there is also the necessity of access to raw data of the ECGs previously acquired. Most of these documents have been saved as Adobe PDF files, since for medical staff it is an easy format for later visualization. However, this format presents difficulties when trying to access original raw data for subsequent studies and signal analysis. In this manner, this paper presents an application that obtains plain numerical data from ECG files stored with PDF format. Data can also be exported to one of the most common file formats in existence, to be easily accessed thereafter.