用于瓦斯抽放钻场的液压钻机牵引移动装置

针对目前瓦斯抽放钻场设备人力移运方式存在人员劳动强度大、效率低、安全性差等问题,介绍了一种液压钻机牵引移动装置的整体结构、液压系统及电控系统的设计方案。该装置采用模块化设计方法,利用钻机油泵提供的动力,通过液压油缸牵引钻场设备向目标地点移动,具有遥控功能。该装置在车集煤矿的应用表明其降低了人员劳动强度,提高了钻场设备移运效率和安全性,具有很高的经济和社会效益。     

Multisensory fusion based virtual tool wear sensing for ubiquitous manufacturing

Pervasiveness of ubiquitous computing advances the manufacturing scheme into a ubiquitous manufacturing era which poses significant challenges on sensing technology and system reliability. To improve manufacturing system reliability, this paper presents a new virtual tool wear sensing technique based on multisensory data fusion and artificial intelligence model for tool condition monitoring. It infers the difficult-to-measure tool wear parameters (e.g. tool wear width) by fusing in-process multisensory data (e.g. force, vibration, etc.) with dimension reduction technique and support vector regression model. Different state-of-the-art dimension reduction techniques including kernel principal component analysis, locally linear embedding, isometric feature mapping, and minimum redundancy maximum relevant method have been investigated for feature fusion in a virtual sensing model, and the kernel principal component analysis performs best in terms of sensing accuracy. The effectiveness of the developed virtual tool wear sensing technique is experimentally validated in a set of machining tool run-to-failure tests on a computer numerical control milling machine. The results show that the estimated tool wear width through virtual sensing is comparable to that measured offline by a microscope instrument in terms of accuracy, moreover, in a more cost-effective manner.     

Knowledge-based hand tool selection in concurrent design of mechanical systems

Selection of hand tools for cost-effective assembly and maintenance of a mechanical system has a significant impact on its life-cycle cost. A knowledge-based automated procedure for the selection of hand tools needed to efficiently carry out fastening operations in a mechanical assembly is presented. The objective is to select a tool that is applicable to a particular fastening operation, minimizes time and cost of the fastening operation, and satisfies accessibility requirements, and to provide design assistance to the design engineer. The role of the tool selection procedure in the concurrent design of mechanical systems is described.     

Force based tool wear monitoring system for milling process based on relevance vector machine

The monitoring of tool wear status is paramount for guaranteeing the workpiece quality and improving the manufacturing efficiency. In some cases, classifier based on small training samples is preferred because of the complex tool wear process and time consuming samples collection process. In this paper, a tool wear monitoring system based on relevance vector machine (RVM) classifier is constructed to realize multi categories classification of tool wear status during milling process. As a Bayesian algorithm alternative to the support vector machine (SVM), RVM has stronger generalization ability under small training samples. Moreover, RVM classifier results in fewer relevance vectors (RVs) compared with SVM classifier. Hence, it can be carried out much faster compared to the SVM. To show the advantages of the RVM classifier, milling experiment of Titanium alloy was carried out and the multi categories classification of tool wear status under different numbers of training samples and test samples are realized by using SVM and RVM classifier respectively. The comparison of SVM with RVM shows that the RVM can get more accurate results under different number of small training samples. Moreover, the speed of classification is faster than SVM. This method casts some new lights on the industrial environment of the tool condition monitoring.     

Knowledge-based machine translation

This paper provides an overview of the KBMT-89 project at Carmegie Mellon University's Center for Machine Translation, as well therefore of the special number of this journal, which reports on the project. The knowledge-based approach to machine translation is presented and defended in a historical context. Various components of the system, key parts of which are described in subsequent papers of the issue, are introduced and paired with their computational motivations.     

一种电位器刻修机控制系统的设计与实现

介绍了计算机控制电位器刻修机软硬件系统的设计与实现,其方法是通过对刻修机床工作过程中的实时数据采集,诊断设备运行过程中出现的问题,分析参数的变化趋势,及时调整控制动作并提供事故处理信息,最终实现高效、准确刻修电位器的目的。     

微型钻头端刃侧刃缺陷的全景式视觉检测技术

在微钻生产中采用机器视觉方法进行缺陷检测时,其难点在于一次拍摄就获得微钻侧刃的完整的、高分辨率的图像.当采用高倍率光学镜头时,又产生视野与检测范围的矛盾.为解决该矛盾,本文创造性地设计了一套内锥镜面反射成像装置,既可获得微钻端刃的清晰图像,又可获得整个微钻侧刃的清晰图像,使得微钻缺陷的全自动视觉检测成为可能.试验结果表...     

基于钻孔数据的复杂轮廓线三角面片的重构

阐述了基于钻孔数据的复杂轮廓线的三维重构,针对三维重构中存在的轮廓线的质心计算、对轮廓线方向性一致操作、分支问题以及如何得到较优的三维曲面等关键技术,提出具体的解决方法,并给出了最终的试验数据,验证了此三维建模方法的可行性。     

Knowledge-based manufacturability assessment: an object-oriented approach

To help the achievement of integrated product and process development, there is a need for tools that can assist designers in creating manufacturable parts with less design routines and tryouts. This paper presents a systematic approach to developing automated manufacturability assessment tools by identifying the functional and informational requirements and proposing an assessment model. The work presented in this paper includes: (1) identification of characteristics and tasks of design for the die-casting process; (2) determination of functional and informational requirements for automatic manufacturability assessment; (3) formalization and modularization of assessment knowledge; and (4) modeling of product definition data to support the assessment. Object-oriented techniques are employed to model the assessment knowledge and manage the complicated and diverse types of product definition data by taking advantage of data abstraction, modularity, inherent concurrence, and the concept of encapsulation and extendibility.     

Knowledge-based system for rapid prototyping

In recent years it has been noticed that rapid prototyping produces better software products. Research on combining Artificial Intelligence and software engineering has also been conducted for a number of years. A knowledge-based system for rapid prototyping is presented. In the system, the Frame-and-Rule Oriented Requirements Language and a methodology are developed to provide an integrated means of prototyping throughoyt the software life cycle. The particular application domain to be modelled is represented in terms of objects and activities. FRORL, which uses the concept of frames and production systems, describes the problem domain's objects and activities in a natural way. With the support of a knowledge base, a software prototype can be rapidly developed using FRORL. The system has been implemented using Prolog on a VAX-11/780 computer.     

Knowledge-based learning using Conceptual Transformers

The notion of concept based on the semantics of objects is defined and illustrated. An underlying thread connecting a subset of concepts is identified. This class of concepts, called the Conceptual Transformer is defined and illustrated with real-world examples. This class finds a natural application in any area where objects can be characterized by functionality. Some interesting application areas are knowledge classification, manufacturing automation, and pattern synthesis. The salient features of this class are elaborated and a knowledge structure for representing concepts is proposed. The effect of these transformers on knowledge-directed classification, which results in the formation of virtual clusters, is examined in detail. We make use of examples from real life to bring out the efficacy of the proposed transformerbased, concept-directed classification.     

Knowledge-based facility planning: a review and a framework

The knowledge-based facility planning (KBFP) problem is reviewed. The aim of KBFP is to provide a more comprehensive planning package for users so that their expertise can be augmented with proven knowledge, and yield significantly better plans. The categories reviewed include facilities equipment selection, software model selection, and the generative task of creating a facility planning solution. The employed problem representation and problem-solving techniques are reviewed. Finally, the development of an integrated framework for KBFP is discussed.     

Alternative multi-label imitation learning framework monitoring tool wear and bearing fault under different working conditions

Bearings and tools are the important parts of the machine tool. And monitoring automatically the fault of bearings and the wear of tools under different working conditions is the necessary performance of the intelligent manufacturing system. In this paper, a multi-label imitation learning (MLIL) framework is proposed to monitor the tool wear and bearing fault under different working conditions. Specially, the multi-label samples with multiple sublabels are transformed into the imitation objects, and the MLIL develops a discriminator and a deep reinforcement learning (DRL) to imitate the feature from imitation objects. In detail, the DRL is implemented without setting the reward function to enhance the feature extraction ability of deep neural networks, and meanwhile the discriminator is used to discriminate the generations of DRL and imitation objects. As a result, the MLIL framework can not only deal with the correlation between multiple working conditions including different speeds and loads, but also distinguish the compound fault composed of coinstantaneous bearing fault and tool wear. Two cases demonstrate jointly the imitation ability of the MLIL framework on monitoring tool wear and bearing fault under different working conditions.     

钻杆长度测量方法

论述了计数法、应力波法、电驻波法以及低压脉冲反射法等钻杆长度测量方法的原理、研究及应用情况,对比了各方法的优缺点,指出电驻波法和低压脉冲反射法不受钻杆材质、直径、类型等因素影响,是钻杆长度测量的研究方向。     

基于知识的人脑三维医学图象自动分析显示系统

设计并实现了一个基于知识的人脑三维医学图象分析显示系统,完成了脑组织的自动分割及显示.系统包含动态模块及静态模块两部分.静态模块即人脑知识库,存贮脑内各组织形态、生理及图象灰度方面的知识.动态模块包含全局数据区、图象处理算子集和控制规则集.在知识的指导下,运用"智能光线跟踪"方法提取、显示脑内主要解剖结构.     

Tool wear monitoring using a fast Hough transform of images of machined surfaces

The texture of machined surfaces provides reliable information regarding the extent of tool wear. In this paper, we propose a structure-based approach to analyzing machined surfaces. The original surface images are first preprocessed by a Canny edge detector. A new connectivity-oriented fast Hough transform is then applied to the edge image to detect all the line segments. The distributions of the orientations and lengths of the line segments are used to determine tool wear. Through our experiments, we found a strong correlation between tool wear and features. The computational complexity of the fast Hough transform is also analyzed.Received: 6 November 2002, Accepted: 18 December 2003, Published online: 13 May 2004 Correspondence to: A.A. Kassim     

Calibration-based tool condition monitoring for repetitive machining operations

Reliable tool condition monitoring (TCM) system is essential for any machining process in mass production to control the part quality as well as reduce the machine tool downtime and maintenance costs. However, while various research studies have proposed their TCM systems, the complexity in setups with advanced decision-making algorithms and specificity in application to limited cutting conditions continue to complicate the implementation of these systems into practical scenarios. This study develops a very simple and flexible TCM system for repetitive machining operations. The proposed monitoring approach reduces the complexity of monitoring model by considering the important characteristic of repeatability in process which has been commonly found in the mass production scenario and implements the calibration procedure to improve the flexibility of the model application to actual machining processes with complex toolpath designs and variable cutting conditions. The selected cutting tools with specific tool conditions are used in the calibration phase to generate reference signals. In actual repetitive production, the collected signal generated by the cutting tool in each operation is compared with reference signals to identify the most similar condition of the reference tool through the proposed similarity analysis. To validate the performance, the current study demonstrates the application of proposed monitoring approach to monitor the tool wear in repetitive milling operations with complex toolpath, and the predicted tool wear progression is found to be in good agreement with experimental measurements during the machining of multiple parts over the entire tool life.     

基于钻孔信息的二维剖面图的三维实体重建*

为了有效地表示地质应用领域的三维实体,针对矿山地质三维数据的特征,提出了基于钻孔信息的地质体分层模型重建策略。给定原始地质钻孔数据,利用自适应神经网络预测地质体横剖面内信息未知区域的品位属性,生成分层数据;结合离散网络模型自动创建相邻数据分层内控制点之间的拓扑关系,由此建立三维实体的表面模型;然后利用OpenGL造型系统对上述模型进行可视化渲染。最后为验证建模方法的有效性,开发了一套地质体三维建模实验系统,并结合实证数据进行了仿真分析。     

基于攻击描述语言的计算机网络攻击演练研究*

提出攻击描述语言(CNADL)面向攻击树建模,采用上下文无关文法设计,描述攻击企图、特征和步骤,由解释器生成相应操作的命令交互执行.基于CNADL在GTNets仿真平台上开发攻击演练系统.实验结果表明,基于CNADL的攻击演练系统能有效地刻画攻击特征,实现了拒绝服务、蠕虫、口令窃取和IP欺骗四种攻击仿真.