Digital Aircraft Sheet Metal Part Manufacturing System and Its Key Technology

The architecture of digital sheet metal manufacturing system is proposed based on the classification of sheet metal manufacturing information.The essence of digital manufacturing is the definition,management and transfer of information,and the key technologies are brought forward and described.It is pointed out that knowledge-based manufacturing elements design is necessary to make digital technology efficient.The management of all kinds of sheet metal manufacturing element information is to build single source of manufacturing data.Multi-state model-based digital transfer and coordination method is designed to provide a foundation for digital manufacturing of aircraft sheet metal part.The application of digital sheet metal manufacturing is exemplified with an aircraft sheet metal part.The application result is compared to that of the traditional analog transfer technology.It is shown that the developed technology can improve part quality,shorten manufacturing time and lower manufacturing cost.     

400kN振动台承力钢架的研制

文章中介绍的400kN 承力钢架是用来作船罩联合试验的承力机构,具有结构庞大、复杂的特点,对自振频率有一定要求,文章介绍了该设备研制过程中的设计、计算、加工及安装工艺技术等。     

Implementation of a novel matrix converter PMSM drive

This paper proposes a neural-network current-regulated switching strategy and an intelligent controller for a matrix converter permanent magnet synchronous motor (PMSM) drive system. By using this new switching strategy, the current harmonics of the system are effectively reduced. In addition, by using the intelligent controller, position control of the drive system can be achieved and an adjustable speed range from 1 r/min to 1500 r/min can be obtained. All the current-loop, speed-loop, and position-loop control algorithms are implemented by a 32-bit TMS320C40 digital signal processor. Several experimental results are shown to validate the theoretical analysis     

Power anomaly effects and costs in low-voltage mobile power systems

Electric power anomalies or disturbances can disrupt the normal operation of equipment, accelerate aging, or even cause outright failures thus resulting in increased costs of maintenance and reduced system reliability. Past research on the effects caused by power anomalies has been mostly focused on industrial, commercial, or residential systems, or on power distribution equipment. A literature survey reveals that there is no comprehensive review related to low-voltage (LV) power systems and utilization equipment applicable to military combat vehicles, such as aircraft and ships. This paper summarizes the results of a new literature survey that focused on the causes, effects, and mitigation methods for power anomalies typical of LV mobile power systems. Electric power anomaly cost data collected from the literature are also presented, from which the costs of anomalies to the national defense are estimated using some simple rationales.     

侧链含硝基氮杂基团的聚醚粘合剂的性能及应用──新型硝基粘合剂研究Ⅲ

对新型的侧链含硝基氨杂基因的富能聚醚粘合剂──端羟基２─甲硝胺基乙基缩水甘油醚均聚醚（ＮＰＥ—Ａ）和端羟基共聚醚（ＮＰＥ—Ｂ）的性能进行了研究。结果表明，ＮＰＥ的热稳定性和化学稳定性良好，优于普通碳氢聚醚粘合剂（ＨＣＰＥ）和新型氟碳聚醚粘合剂（ＦＣＰＥ）；其固化后的力学性能良好。简要地叙述了以ＮＰＥ—Ｂ为粘合剂的固体火箭推进剂的配方和性能。     

EUROCAT－X系统故障的诊断和分析

NESACC项目是我国空管史上规模最大的空管建设项目。该项目总投资近20亿人民币,分别在北京、上海、广州兴建三大区域管制中心,使用Thales公司研制的欧洲猫(EUROCAT-X)空管自动化系统,配备先进的自动化设备,使空管工作更为科学、直观、安全。EUROCAT-X系统自运行以来,运行情况基     

如何做好雷达管制下航空器的飞行动态监控

一、前言在雷达管制空域,只要管制员发出“radar contact”或“radaridentified”这样的指令,就担负起了对该航空器的一切动态过程的监控责任。如果对该机的飞行动态监控不到位,造成的一切不安全后果,雷达管制员都将难辞其咎。近来在全国范围内发生的几起不安全事件,多是由于管     

基于多相正交序列移位序列的CDMA通信系统

介绍多相正交序列的构造方法,对多相正交序列的自相关和互相关特性进行分析。提出采用多相正交序 列的移位序列作为扩频序列的通信方式,并给出接收端序列同步的实现方法。这种方式能解决低相数多相正交序列互 相关特性不理想,而高相数多相正交序列难以搜索的困难。     

加速器切线照相技术研究

根据工作实践研究了固体发动机切线照相无损检测中黑度分布、散射线防治、象质计使用、检测概率计算、脱粘临界值确定等技术问题.