江苏油田三种典型钻具组合复合井导向力计算分析

结合江苏油田导向钻井技术现场试验中采用的三种典型的滑动导向钻具组合,在计算复合钻井导向力的基础上,探讨了两个主要因素对复合钻井导向力的影响规律,理论计算结果与现场试验结果基本吻合,通过设计钻具组合的结构和施工参数,可以提高井眼轨迹控制精度。     

基于轨迹模式空间解耦及模式能量序列的振荡分析(三)时变性分辨率从摆次细化到时间断面

系列文章的前两篇以振荡模式的空间解耦代替频域解耦,并通过互补群模式的摆次能量演化来反映复杂振荡行为的特征。由于其对时变性的分辨率较低,也不利于讨论多模式之间的交互作用,故文中提出在每个积分步末端所对应的时间断面处,按实际变量值重新冻结映象系统的非哈密顿因素,按虚构的哈密顿系统来估计该断面后的不平衡功率-转角的曲线。进而评估各互补群模式的振荡总能量(或其裕度)的时间序列,将轨迹振荡能量序列分析方法的时间分辨率从按模式摆次细化为按积分步长,更好地反映振荡的局部时变性。针对分别计及调速器或计及机械功率周期性扰动的两个算例,揭示了系统“反常”振荡行为的机理。     

THE INFLUENCE OF GROSS BODY WEIGHT ON OXYGEN CONSUMPTION AND ON PHYSICAL WORKING CAPACITY OF MANUAL LABOURERS

A regression line relating oxygen consumption to rate of work has been calculated on 88 men from pairs of oxygen consumption and work-rate measurements at four different levels of work. A regression line has also been calculated for maximum oxygen intake against gross body weight for 338 men. From these regression lines it is possible to estimate the proportions of their maximum oxygen intakes a light and a heavy man would use in stepping on and off a 1 ft stool at 6, 12 and 24 times per minute. The slopes of the lines are such that both men would use similar proportions of their maximum oxygen intakes at each of the three rates of stepping ; the percentages are 26 per cent, 36 per cent and 55 per cent respectively.

The distribution of the gross body weights of the 338 men has been used to calculate a body weight such that 95 per cent of the men having weights above this value would have maximum oxygen intakes of 2-0 litres/min and more and therefore be capable of a moderate rate of work. A gross body weight of 132 lb is the estimate and 43 per cent of the population lie above this weight.

The ‘ tolerance ’ limits about the o.xygen consumption/gross body weights regression line are relatively narrow indicating that gros3 body weight is the major determinant in oxygen consumption when men lift their body weights against gravity. The ‘ tolerance ’ limits to maximum oxygen intake against gross body weight are wido, which suggests that the proportion of body fat influences the maximum oxygen intake value ot a given body weight.     

弹道方程边值问题中的直射弹道公式

本文探求了属于微分方程边值问题的直射弹道公式,以形简、意明、精确度高、研究方法的多样性和事物规律的不同表现形式为特征。在直射弹道的定义和数学描述之后,先从它的微分方程出发推导出了公式;再从方程的数字解出发探寻并确立了其规律性。     

非开挖导向钻进轨迹的设计原则与控制方法

讨论了轨迹设计与控制的重要性,提出了需要做的准备工作,导向孔的设计埋深、出入土角、弯曲半径的设计原则,控制测量的方法、原则及纠偏的方法,以期减少工程事故,减少施工成本,缩短施工周期,取得更好的经济社会效益。     

某型制导火箭弹弹道仿真

制导化改造是提高火箭弹精度最有效的一种方法.弹道仿真在制导火箭弹研究设计中占有非常重要的地位,仿真结果的正确性与合理性直接影响了制导控制系统的设计开发.为了对制导火箭弹的弹道进行仿真,首先建立了制导火箭弹的运动数学模型,而后结合风洞试验得到的动力系数进行了无控弹道仿真,得到了弹道、速度、弹道倾角和攻角等变化曲线.仿真结...     

An Improved Method for Load Taxonomy Using Sample Shifting Technique and Signature Analysis

This paper illustrates an improved method of classification of electrical appliances, particularly for domestic loads, to construct load taxonomy on the basis of their signature analysis. Each electrical load is characterized by its own distinct signature and hence load signature analysis is useful in monitoring the health of the equipment, power quality, in determining individual energy usage etc. type of services. On the other hand, load taxonomy classifies these loads in several clusters on the basis of some features extracted from their signatures. In traditional methods of construction of load taxonomy, different signature patterns based on power metrics, V-I trajectories, Eigen vectors, etc. In this proposed method, with the adoption of sample shifting technique the required number of feature extraction is reduced to a lower value to find out various signature patterns than those are required in traditional load taxonomies. Moreover, a better taxonomy, having well separated groups of loads is achieved with lower number of extracted features.     

旋转横流中侧边射流偏斜和扩散的实验研究

为研究旋转横流中侧边射流的偏斜和扩散特性,搭建了横向射流流动显示实验台架,采用可调同步激光器和CCD摄影技术获得了不同射流速度比率时(r=15、30、45、60、75)横向射流的流场结构,基于横流槽道特征尺寸和射流速度的雷诺数Re介于22 537和112 683之间.实验结果表明,旋转横流中侧边射流的射流速度比率较大(r>30)时,射流深度基本不变,异于均匀横流中侧边射流的气流偏斜特性.另外,并非越大的射流速度比率就能获得越大的射流扩展宽度,当r=60时,系统的射流扩展宽度最大,而且在较大的射流深度区域内维持较大的扩展宽度,有利于物质的混合扩散.     

伺服系统CANopen协议软件植入方法分析

分析了在交流伺服系统中实现CANopen运动控制子协议CANopen DS402的两种方式:硬件嵌入实现和软件植入实现.通过对软件植入方法进行分析,探讨了在伺服控制程序中植入协议模块的关键问题,针对这些问题提出了相应的解决方案,并在伺服驱动器中实现了协议内容.实验结果验证了该方法的正确性和实用性.     

Third-order trajectory planning for high accuracy point-to-point motion

This article studies a third-order trajectory planning method for point-to-point motion. All available instances for third-order trajectory planning are first analyzed. To distinguish those, three criteria are presented relying on trajectory characteristics. Following that, a fast preprocessing approach considering the trajectory as a whole is given based on the criteria constructed and system constraints. Also, the time-optimality of the trajectory is obtained. The relevant formulas are derived with the combination of geometrical symmetry of trajectory and area method. As a result, an accurate algorithm and its implementation procedure are proposed. The experimental results show the effectiveness and precision of the proposed method. The presented algorithm has been applied in semiconductor manufacturing equipment successfully. __________ Translated from Journal of Huazhong University of Science and Technology (Natural Science Edition), 2007, 35(12): 58–61 [译自: 华中科技大学学报 (自然科学版)]