利用连杆转角曲线进行平面连杆机构轨迹综合的研究

提出并解决了利用连杆转角曲线β（）进行平面连杆机构轨迹综合的计算机方法。在解决了由给定封闭轨迹向连杆转角曲线转化的关键技术和方法的基础上，用该方法建立了一系列已知四杆机构的连杆转角曲线数据库，从而可以在已建立的数据库中寻求出能够实现给定轨迹的四杆机构，达到近似实现轨迹曲线“无穷多点”的“精确”机构综合。     

具有运动要求的平面连杆机构轨迹综合

本文以最小杆长差法为基础,提出了具有速度、加速度要求的平面连杆机构轨迹综合的一种新方法。该方法通过将平面铰接四杆、六杆机构分解为三个基本解析组和两个基本综合组,然后再通过进一步对解析组和综合组的分部综合来求出机构的全部参数,该方法还可求解双轨迹综合与不等精度轨迹综合问题。     

平面连杆机构再现轨迹的可靠性优化设计

针对一般的平面连杆机构再现轨迹优化设计中一些不足之处,本文认为设计过程中应当同时考虑制造过程中公差给机构输出偏差带来的影响,在一般优化设计方法的基础上,本文运用可靠性设计的原理,建立了连杆机构可靠性优化设计的数学模型,为连杆机构再现轨迹的设计,提供了一个新的,更加合理的算法。     

平面连杆机构轨迹综合的自相关法

提出了利用连杆轨迹曲线的自相关变换进行平面连杆机构轨迹综合的计算机方法。用该方法建立了已知连杆机构的轨迹曲线的特征参数数据库，从而可以在已建立的数据库中快速地查找出能够实现给定轨迹的连杆机构，以达到近似实现多点轨迹曲线的机构综合．     

平面连杆机构多媒体分析系统的开发与研究

探讨了平面连杆机构多媒体分析系统的开发过程；利用VB开发工具和DirectX7的接口技术进行编程，建立了三维编辑器，实现机构的动画仿真、轨迹模拟和运动曲线图的绘制。为连杆机构的运动学分析开发了一套简便、实用的软件系统，可应用于工程模拟、设计和计算机辅助教学(CAI)。     

基于支持向量机的连杆曲线识别

四连杆机构的轨迹图谱相当繁浩,如何从数千条轨迹曲线中找到与要求实现的轨迹相同或相似的图形是限制轨迹图谱应用的关键之一。提出一种基于支持向量机的连杆曲线识别方法,把所要实现的轨迹离散化作为输入,通过所设计的支持向量机的判别,找到图谱中相对应的轨迹曲线。     

平面连杆曲线的分布规律及其曲线绘制的一种简捷方法

基于平面四杆机构的连杆对机架作平面运动的一对瞬心线,研究了连杆平面的运动及连杆曲线的形成情况,从而给出了平面四杆机构的连杆曲线形状变化及其类型分布的规律,并提出一种绘制连杆曲线的简捷方法。     

圆弧或直线轨迹连杆机构设计的新方法

论述了能产生对称连杆曲线的四杆机构主要特征,提出了设计圆弧或直线轨迹连杆机构的新方法,并同时考虑传动角的影响。本方法简单直观,且精度高,适用于有轨迹和传力特性要求或实现间歇运动连杆机构的设计。     

连杆曲线轨迹综合的特征图谱

提出了连杆曲线轨迹综合的特征图谱。该方法通过对连杆平面上所有连杆曲线的类别和尺度特征分析,建立了连杆曲线特征图谱。其方法是,用尖点曲线、自切点曲线及凹凸分界线把连杆平面划分出若干个区域,不同区域内的连杆曲线具有各自的类别特征。而尺寸特征则使用如L、W、J、J1、J2等外形参数来描述,并用绘制等值线的方法建立连杆曲线特征图谱。特征图谱不仅有利于轨迹综合,利用它也可预知任意位置的连杆点的运动轨迹。     

Dynamic analysis and grinding tracks in the magnetic fluid grinding system: Part II. The imperfection and ball interaction effects

To model the effects of the geometrical imperfections on the ball motion and its grinding track, it is therefore necessary to combine a dynamic model of the support system of balls with the previous model. For the geometrical imperfections on the ball, because of the interaction between the contact loads and the ball-spin speed, it causes the friction contact condition to remain at the interfaces with lower contact loads and lower ball-spin speeds in the separation case at the initial stage. Consequently, the variation in the ball-spin angle and the area covered by the grinding tracks is small. However, when the intermittent separation occurs at the geometrical imperfections on the ball orbit, it causes a large oscillation in the ball-spin angle and the ball-spin speed. Consequently, the effect of the imperfections in the ball orbit on the area covered by the grinding tracks is larger than that of the ball geometry. Ball–ball contacts cause a large oscillation in the ball-spin angle resulting in a uniform distribution of the grinding tracks. Hence, the effect of ball–ball contacts is one of the most important mechanisms in achieving a uniform distribution of the grinding tracks.     

TY2F工程作业车轴箱弹簧分析及设计

作业车轴箱弹簧是工程作业车底架及走行部的关键部分，它的性能好坏直接影响到整个作业车在铅垂方向的运行平稳和对线路的动作用力，为此必须对轴箱弹簧作比较详细的计算与分析，通过不断的比较、优化最终确定轴箱弹簧的参数。     

Improvement of overlapping nuclear track densitometry

Detection of tracks produced by α particles, protons or nuclear fission fragments in plastic detectors, viz., solid‐state nuclear track detectors, constitutes a very important tool in various areas. It is not easy for humans to count CR‐39 nuclear tracks manually, especially when the track density is very high. An automated computer program called KTTMS2, written in C++ and running with a user friendly interface, has been developed for recognition and parametric measurements of etched tracks in images captured from the surface of solid‐state nuclear track detectors. Well‐known edge detection methods were applied to estimate the precision and accuracy of nuclear track densitometry using the CR‐39 detector. Among the various routine edge detection methods, the Canny method was chosen because it was the most accurate technique. Because accuracy becomes more important as the track density increases, this allows more overlapping tracks to be detected. KTTMS2 (the proposed system) has an efficiency of 95% and can identify the noise as a background track (5%). Experimental results showed that the error percentage was reduced from 7.63% to 3.23% for high‐density tracks when the count was adjusted by the estimated overlapping tracks.     

The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF

A magnetic recoil spectrometer (MRS) has been built and successfully used at OMEGA for measurements of down-scattered neutrons (DS-n), from which an areal density in both warm-capsule and cryogenic-DT implosions have been inferred. Another MRS is currently being commissioned on the National Ignition Facility (NIF) for diagnosing low-yield tritium-hydrogen-deuterium implosions and high-yield DT implosions. As CR-39 detectors are used in the MRS, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). The coincidence counting technique was developed to reduce these types of background tracks to the required level for the DS-n measurements at OMEGA and the NIF. Using this technique, it has been demonstrated that the number of background tracks is reduced by a couple of orders of magnitude, which exceeds the requirement for the DS-n measurements at both facilities.     

基于UG的蓝宝石衬底基片双面研磨轨迹研究

通过数学理论建模与UG建模,建立了蓝宝石衬底基片双面研磨的运动模型并获得了在三种传动比情况下行星齿轮上不同点的轨迹。通过分析研磨轨迹和研磨速度可知在传动比为1时行星齿轮各点的轨迹为均匀分布的圆形且速度相等,所有点的运动周期相等而且比其它情况下的周期短,有利于提高研磨效率和形状精度,结果成功地解决了由于行星齿轮内的衬底基片各点处速度不一样而导致的平面度差的问题和行星齿轮中心不能放置蓝宝石衬底基片的问题。     

An efficient algorithm for scheduling jobs on a machine with periodic maintenance

As machine maintenance is required in many industries, it is usually arranged in a planned schedule. In this paper, we discuss a scheduling problem where periodic maintenance and jobs are scheduled on a regular basis. In our research, a periodic maintenance sequence consists of several maintenance periods and each maintenance period is scheduled after a fixed time interval. The objective is to minimize the total flow time and the maximum tardiness. A heuristic that utilizes the theorem is proposed to solve the problem by providing a small set of efficient sequences. A decision-maker may choose one of the sequences according to his preference. We also propose a branch-and-bound algorithm is to find the optimal sequence. Computational results show that the presented heuristic is highly accurate and efficient.     

基于打滑条件下的履带车辆转向分析

研究履带车辆转向性能时传统履带车辆转向理论不考虑履带接地段的滑转与滑移,计算结果与实际存在一定差别。在分析履带与地面相互作用的基础上,基于滑转滑移条件讨论履带车辆平稳转向的实际过程,导出了履带牵引力、制动力、转向阻力矩、转向半径和转向角速度的表达式,采用迭代法求其数值解,和传统转向理论的相关结果作了定量比较,并进行了实车试验。结果表明,考虑履带接地段打滑后相对转向半径约为不考虑打滑时的转向半径的1．5倍,即约为履带车辆接地长L与履带中心距B之比,转向角速度约为不考虑打滑时的2／3,考虑履带接地段打滑时转向半径与转向角速度同实车试验测定的数据相比误差在3％左右。表明建立的考虑履带打滑时的转向模型更符合履带车辆转向实际。     

翻车机端环轨道的焊接

以黄骅港1期翻车机端环轨道为例,对端环轨道的接头形式和高碳钢焊接工艺进行了分析和设计,解决了翻车机在端环轨道接头处的振动现象,改善了设备运行平稳性,延长了轨道寿命。     

有质量偏心的转子-轴承系统瞬态性能的研究

考虑轴承的瞬态温度场,用仿真法对有质量偏心的转子-轴承系统的瞬态性能进行了研究.分别将考虑轴承三维、二维绝热和不考虑温度场时用仿真法得到的轴心运动轨迹与用线性化油膜动特性系数特征值法得到的轴心运动轨迹做了比较.结果表明,温度对轴心轨迹的影响很大,考虑不同温度模型的轨迹有很大的不同;另外验证了用线性化油膜动特性系数特征值法求轴心轨迹只适用于小扰动情况下的结论.     

某高速履带式装甲车悬挂系统动力学仿真

基于多刚体动力学理论建立了高速履带车辆悬挂系统与地面作用的动力学模型,基于贝克理论建立路面,研究了高速履带车辆在工况为爬行60°坡时悬挂系统的动力学响应问题,分析了车辆爬60°坡在2种不同路面上左、右履带的平均转矩,并且和计算求得理论转矩进行比较,分析得出仿真数据和理论数据误差率在5%内,模型特别考虑了履带对履带车辆动力学响应的影响.