基于熵不确定性概念的机器人位姿精度理论体系

本文在指出传统的机器人位姿精度理论研究不足的基础上，提出利用信息熵的概念来研究机器人的位姿精度，简要介绍了基于熵不确定性概念机器人位姿精度理论的体系结构，具体包括精度模型的建立，位姿精度分析方法，位姿精度优化综合方法以及位姿精度分析的计算机仿真系统，最后，说明了用基于熵不确定性概念的机器人位姿精度研究方法解决现有机器人位姿精度理论研究虽存在问题的办法。     

数控机床精度衰退的研究进展

精度衰退是影响高精度数控机床精度保持性的主要原因,国内外近年来进行了大量研究.文中阐述了数控机床精度衰退相关研究的进展和现状,重点评述了摩擦磨损、机械结构和运行状态对数控机床精度衰退的影响,并针对存在的主要问题提出了建议和发展方向.     

钛合金焊接快速成形精度控制研究新进展

精度控制是钛合金焊接快速成形的重要研究内容。阐述了钛合金焊接快速成形过程中工艺参数、预处理、仿真模拟、成形预测、模型分层对成形精度的影响,论述了精度控制表征参数研究现状,指出了精度控制的未来发展方向,为钛合金焊接快速成形提供了技术支撑。     

电火花加工机床热特性研究

一、前言电火花加工机床的加工精度,不但与静态精度有关,还与动态精度有关,特别在连续较长时间加工的状态下,还与热态精度紧密相关。研究电火花加工机床热变形,对合理使用现有机床、提高加工精度有积极的意义。本文分析了某型号电火花加工机床的实验结果,研究了该机床热特性,并提出了相应建议。     

机器人位姿精度理论研究现状及展望

本文分析了机器人位姿精度理论的研究现状, 指出其欠缺之处, 从信息论的观点出发, 探索利用信息熵的概念来研究机器人的位姿精度理论, 建立了机器人位姿信息传输模型, 并对它有望弥补解决目前机器人位姿精度理论中研究不足的可能性进行分析探讨。     

直齿轮有限元接触分析与偏差对传动精度影响

以一对直齿圆柱齿轮为研究对象,建立其误差齿轮三维有限元接触精度模型,采用ANSYS分析齿廓偏差及偏心误差对直齿轮副传动精度影响。利用APDL语言建立齿轮三维有限元精确接触模型;以节点移动及齿轮整体移动的方式编程实现误差齿轮模型。通过求解不同精度等级齿轮副实际啮合时的传动精度,得出精度等级对传动精度的影响呈非线性关系,研究将对精密齿轮的传动设计提供依据。     

电火花加工用复杂电极形状精度检测研究

针对电火花加工复杂电极形状精度检测成本高,场地受限的问题,研究出了一种接触式测量方法,开发出了一种精度检测设备,提出了一种精度检测方法。研究了特征点数据的提取方法,并开发出了提取软件。确定了目标点计算矩阵。提出了电极形状精度的评定方法,并进行了仿真验证。进行了实际的精度检测试验,结果表明文中的研究成果可以在生产现场高效的完成复杂电极的形状精度检测,具有较强的实际应用价值。     

弧焊机器人机械精度的测试方法

文章简要介绍日本焊接协会研究的弧焊机器人机械精度测试方法。测试项目有再现位置精度、再现轨迹精度、轨迹重复精度、线速度精度、线速度变动、焊线横摆精度和最小回转半径等七项。图7幅。     

数控车床总装关键工序的装配技术及精度分析

研究装配精度,采用有效的装配方法,对保证产品的质量有着十分重要的意义。文章主要介绍了CKA6150数控车床床头箱在整机总装关键工序中的装配工艺技术及精度检验方法,对床头箱与床身的位置精度、冷态精度和热态精度的相互关系、主轴热位移偏差方向等方面进行了分析研究。在数控车床的现场装配过程中,应用这种装配技术,对于保证机床整机精度的可靠性,提高机床生产效率是一种有效的途径。     

数控车床刀尖高度对零件加工精度的影响

研究了数控车床刀尖高度对零件加工精度的影响.主要从尺寸精度和形状精度两个方面进行了分析,给出了误差的计算公式.得出了可以通过选择合适的对刀尺寸来提高加工精度的结论.     

不锈钢AOD精炼过程物理模拟研究进展

综合评述了关于不锈钢AOD精炼过程的物理模型研究和取得的进展 ,阐明了AOD过程的一些重要特征 ,认为过去一些模拟研究因考虑运动相似性不够 ,影响了模拟结果的准确性 ,魏季和等的工作充分考虑了运动相似性 ,所得模拟结果与实际更为吻合。     

传感器阵列对岩体微震/声发射源定位精度的影响（英文）

随着开采深度增加,岩体动力灾害日益突出。微震监测已成为岩爆、顶板坍塌等岩体动力灾害监测的重要技术手段。传感器阵列布设作为信号采集的第一步,严重影响信号源的定位精度。讨论和总结有关由传感器阵列布设引起的微震(MS)和声发射(AE)震源定位误差的重要研究,并分析传感器数量、传感器布设形态以及传感器与震源距离对MS/AE源定位精度的影响机制。随后,结合工程实践和实验室测试,给出传感器阵列的一些布设原则,并通过现场应用进行验证。另外,综合考虑影响传感器阵列布设数量、形状和距离的因素,找到最优布置方案,可大幅度改善信号采集效果,提高信号源定位精度。最后,对提高MS/AE源定位精度所面临的挑战和传感器阵列方面相应的应对策略进行展望。     

An Investigation of the Capability Profile of the Three Dimensional Printing Process with an Emphasis on the Achievable Accuracy

A benchmark procedure has been designed to assess the dimensional as well as the geometric accuracy of currently one of the most widely used rapid prototyping processes - the Three Dimensional Printing. It tests not only linear accuracy but also precision, and repeatability of the process, as well as its ability to create manufacturing features such as fillets and draft angles. The presented research results reflect the necessity to adequately respond to engineering requirements for clearly meeting dimensional and geometric tolerances and root on several in-house case studies proving the comparison with established high-end RP processes.     

Feature-based tool path generation approach for incremental sheet forming process

Incremental sheet forming (ISF) is a highly versatile and flexible process for rapid manufacturing of complex sheet metal parts. Although tool path plays an important role in the ISF process, there is only limited development in the tool path generation strategy and the conventional contour based strategies have been proven to cause problems in surface quality and geometric accuracy. This paper presents a new feature-based tool path generation algorithm for incremental sheet forming process. In this algorithm, tool paths are generated according to the specified critical edges. To obtain a better understanding of forming mechanism using the new tool path generation method, the thickness distribution, geometric accuracy and surface quality of the ISF formed shapes by using the feature-based tool path approach are compared with the traditional ISF tool path method based on three case studies including a truncated cone with double bottoms, a non-symmetrical cone and a car fender. The results suggest that the new tool path stretches the sheet in a different way and results in different thickness distributions. The results of these case studies also demonstrate the advantages of the feature based tool path generation especially in surface quality, geometric accuracy and forming time.     

Form-accuracy analysis and prediction in computer-integrated manufacturing

The manufacturing of high-quality products at low costs is one of the greatest challenges of every company today. Form accuracy is among the quality parameters of machined parts and is directly related to functional performance. Control and improvement of form accuracy is to be performed under the computer-integrated manufacturing (CIM) concept. This paper investigates the form accuracy of mechanical machining and studies the essential aspects and procedures of form-accuracy simulation. The emphases are on the integration of form-accuracy analysis and the simulation into the CIM database construction and virtual manufacturing. Form-accuracy analysis in this paper reveals that the inherent drawbacks in design will directly affect the geometric quality of a workpiece, and proper process planning can enhance the manufacturability of parts with the required geometric quality. The simulation procedure implemented in this paper can be used at the design stage to predict the form accuracy of a machined part and functional performance. The procedure can also be used at the process planning stage to predict and control form accuracy during the machining process.     

超声波激振铰刀干式铰孔试验研究

通过将超声波能量施于铰刀，使其以超声频振动进行干式铰孔的工艺方法，试验研究超声波激振干式铰孔对加工精度、表面粗糙度的影响规律。     

一种新型快速位置系统的研究

针对某大型风洞中电液伺服系统快速动作时流量大、定位精度高的特点，本文提出用伺服论阀与电磁换向阀并联控制的方案。并通过试验研究，确定了一些关键参数的选择方法。在最终位置的精确控制中，采用了自适应控制算法，取得了满意的效果。     

Complete 3D measurement in reverse engineering using a multi-probe system

To meet the demand of measuring the complex prototypes completely in reverse engineering, a multi-probe measurement system integrated with a coordinate measuring machine (CMM), a structured-light sensor, a trigger probe and a rotary table is presented in this paper. The structured-light sensor is designed with optimal structure, and its model is established based on the CMM to simplify its parameters, this enables the sensor to be calibrated expediently at any condition. Three measuring modes are proposed considering the efficiency of the structured-light sensor, the high accuracy and flexibility of the trigger probe and the rotation of the table for finding proper scanning views. The structured-light sensor is usually applied to scan the profile of a part from different views, while the trigger probe is used to measure the edge and key features of the part. The data generated by different modes can be merged into a whole data body. The system possesses the function of obtaining the coordinate of nearly any point on a complicated part. Experiment studies on the accuracy of the structured-light sensor, data patch assembling and data merging show that the total accuracy of the system is ±0.033 mm.     

12%Cr超超临界转子钢的晶粒长大规律

研究了12%Cr钢在1 000~1 250℃温度下保温时间对奥氏体晶粒长大的影响。通过实验研究,获得了该钢奥氏体晶粒在高温下的长大规律,建立了晶粒长大的动力学模型,并通过对该模型的拟合值和试验值的对比,表明此模型对其长大规律的预测具有较高的准确性。     

U形件拉深成形回弹影响因素的计算机仿真(英文)

回弹是板料冲压成形中的主要缺陷之一 ,控制回弹涉及到回弹量的准确预算。利用DANAFORM软件 ,对U形件拉深成形回弹影响因素进行了计算机仿真 ,得到了压边力、凸凹模间隙、摩擦系数、材料特性等参数对回弹影响的数值结果 ,并对模拟结果进行了分析。