电液伺服系统的仿真与自校正PID控制器的设计

对一个试验用电液伺服系统进行了理论建模和仿真研究 ,引入了一个非线性状态方程模型来描述电液伺服系统的动态特性 .通过仿真结果与实际系统的响应相比较 ,验证了所建立的理论模型的准确性 .在此仿真模型基础上 ,设计了一个适用的自校正PID控制器 ,并且对其控制特性进行了仿真研究     

Experimental investigation on anti-penetration performance of polyurea-coated ASTM1045 steel plate subjected to projectile impact

In this study, the anti-penetration performance of polyurea/ASTM1405-steel composite plate subjected to high velocity projectile was analyzed. Two kinds of modified polyurea material (AMMT-053 and AMMT-055) were selected and a ballistic impact testing system including speed measuring target system and high-speed camera was designed. This experiment was conducted with a rifle and 5.8 mm projectile to explore the effects by the polyurea coating thickness, the polyurea coating position and the glass-fiber cloth on the anti-penetration performance of polyurea/ASTM1405-steel composite plate. The result showed that the effects of polyurea coating position were different between two types of polyurea, and that the effects of glass-fiber position were disparate between two types of polyurea as well. For AMMT-053 polyurea material, it was better to be on front face than on rear face; whereas for AMMT-055 pol-yurea, it was better to be on rear surface although the difference was very subtle. Additionally, formulas had been given to describe the relationship between the effectiveness of polyurea and the thickness of polyurea coating. In general, AMMT-055 had better anti-penetration performance than AMMT-053. Furthermore, five typical damage modes including self-healing, crack, local bulge, spallation and local fragmentation were defined and the failure mechanism was analyzed with the results of SHPB test. Additionally, the bonding strength played an important role in the anti-penetration performance of polyurea/steel composite plate.     

磁悬浮列车滑模变结构控制器设计及实现

本文在建立磁悬浮线性模型基础上,设计变结构控制器,进行了仿真计算,并用模拟电路进行实验,给出了仿真和实验结果     

Scheduling to minimize release-time resource consumption and tardiness penalties

We consider the problem of scheduling a set of jobs with a common due-date on a single-machine where the release time of a job is related to the amount of resource consumed. The objective is to minimize the total resource consumption and the total tardiness. While the problem is strongly NP-hard in general, we discuss two different special cases for which special properties are identified and used to develop efficient pseudo-polynomial time algorithms. © 1995 John Wiley & Sons, Inc.     

洞库储罐壁局部失稳分析

因储罐使用时间过长,或者在使用管理中操作不当等原因,目前某些洞库储罐出现不同程度的失稳现象,甚至不能正常工作,严重干扰了油库的储存以及收发作业,出现设备闲置现象。根据拉姆公式对失稳现象进行分析探讨,剖析造成失稳的主要因素,针对某洞库罐壁失稳的实际情况,对油库的实际工作提出建议,对于加强储罐的管理工作有重要的参考价值。     

单摄像机三维视觉技术

本文针对装配机器人的实际应用情况,提出了一种利用激光结构光提供的空间几何信息和图象中包含的物体表面与物体形状的信息来综合分析与提取空间物体的三维信息的方法。该方法已经实际应用于GKD-1型机器人视觉系统中。     

某装甲侦察车液压升降机构液压系统分析

详细介绍了某装甲侦察车液压升降机构的工作原理和液压系统,找出了存在的一些主要问题,并阐述了解决问题的初步建议.     

武器装备系统效能评估的几种方法

介绍了层次分析法、美国工业界武器系统效能咨询委员会方法、指数方法、专家调查法和SEA计5种评估武器装备系统效能的方法．只有熟练地掌握和正确运用这些方法才能对不同类型武器系统效能评估作出准确的判断,从而为武器装备的研制、采购提供客观的、定量的数据,避免造成人力、物力、财力的浪费．     

测定Kevlar-49环氧复合材料纤维含量方法的研究

本文介绍了测定Kevlar-49环氧复合材料纤维含量的一种改进的方法。通过试验研究,作者在美国New Mexico Sandia验室所报导的方法基础上进行了改进。改进的方法在快速、经济、低毒和准确性等方面均较Sandia原方法优越。     

充分发展湍流管道内壁边界的红外定量识别

基于导热的管道内壁边界识别已发展成熟,但更贴合实际的湍流管道内壁边界的定量识别尚未见报道。通过关联COMSOL和MATLAB,利用有限元方法和Levenberg-Marquardt算法对二维轴对称充分发展的湍流管道内壁边界形状的稳态识别进行研究。数值实验证明了本方法的有效性。结果表明,在含内壁缺陷的湍流管道中,外壁最大温差和由缺陷引起的绝对温差并不是同步增加的;在进行内壁边界反问题识别时,由于绝对温差中负增长的出现,绝对温差越大,识别结果未必越好;识别精度在不规则内壁终点处略微变差。