基于CEI的航天器交会对接段的轨道监控

文章探讨了CEI技术在飞船交会对接远程导引段的实时监控的能力,采用单一绝对滤波器的方案进行实时轨道计算,仿真结果表明：采用滤波稳定后固定模糊度的方法可以提高轨道的滤波解精度,相对轨道位置精度可达十米级,速度精度可达厘米每秒级,满足远程导引段的精度指标。     

基于UG的虚拟制造

介绍了基于现代数控虚拟制造技术的基本内容,并以某零件为例进行了详细工艺分析与虚拟制造仿真技术研究,进行了该零件的切削仿真,开发了后置处理器,实现了机床碰撞系统的虚拟仿真。为解决此类复杂零件的高效数控加工提供了新的方法。     

C波段高增益平板微带天线的设计

文章以微带天线的基本电磁场理论为依据,对微带天线的结构进行了深入的研究。通过建模仿真,设计频带为4.5GHz～5.0GHz的天线,要求在该频段天线的驻波比VSWR〈1.6,平均增益为28～29.5dB。在设计中采用微带U_Slot矩形贴片作为单元,引入π结构,采用近邻耦合方式进行馈电,组成天线阵列来实现。设计结果通过实验室提供的天线测量设备进行测试,软件仿真结果与实际测量结果有较好的一致性。     

基于径向基函数响应面的机翼有限元模型修正

用ANSYS三维实体单元SOLID45建立机翼基准有限元模型并计算其自由振动的前6阶模态频率.用均匀设计方法将结构参数分组并分别计算各组结构参数对应的模态频率,建立高斯径向基函数响应面模型.用最小二乘法则拟合系数并检验响应面拟合精度,对基准模型的结构参数施加摄动量建立待修正有限元模型.用响应面模型和基准模型计算所得模态频率的相对误差建立适应度函数的表达式,将混沌搜索机制引入粒子群算法对结构参数的摄动量进行寻优计算,搜索所得优化解代入即得修正后模型,将修正后模型与基准模型在测试频段内段外的模态频率近似度进行比较,证实了修正后模型的有效性.      

MEWMA控制图ARL计算及参数优化

平均运行链长(ARL)是控制图性能评价的一个重要指标,深入研究ARL是控制图参数优化、性能评价和实际应用的重要工作.在采样数据标准化处理的基础上,应用马尔可夫链进一步研究了多元指数移动平均(MEWMA)控制图中ARL计算的数学模型,采用Matlab实现了算法,就算法的收敛性及计算结果进行分析.以ARL为优化指标,给出了MEWMA控制图参数优化的具体步骤、计算实例和参数优化结果.      

A study on optimal control of the aero-propulsion system acceleration process under the supersonic state

In order to solve the aero-propulsion system acceleration optimal problem, the necessity of inlet control is discussed, and a fully new aero-propulsion system acceleration process control design including the inlet, engine, and nozzle is proposed in this paper. In the proposed propulsion system control scheme, the inlet, engine, and nozzle are simultaneously adjusted through the FSQP method. In order to implement the control scheme design, an aero-propulsion system component-level model is built to simulate the inlet working performance and the matching problems between the inlet and engine. Meanwhile, a stabilizing inlet control scheme is designed to solve the inlet con-trol problems. In optimal control of the aero-propulsion system acceleration process, the inlet is an emphasized control unit in the optimal acceleration control system. Two inlet control patterns are discussed in the simulation. The simulation results prove that by taking the inlet ramp angle as an active control variable instead of being modulated passively, acceleration performance could be obviously enhanced. Acceleration objectives could be obtained with a faster acceleration time by 5%.     

Rapid deployment and continuous shape maintenance of tethered-space net robot based on single-pulse action

The tethered-space net robot is one of new technologies for capturing space debris. Rapid deployment and continuous shape maintenance of the tethered-space net robot system are essential in capturing space debris. A single-pulse rotation deployment strategy of the tethered-net robot system is proposed in this paper. The rapid deployment and continuous shape maintenance of the tethered-net are investigated through dimensional analysis, numerical simulation, and regression analysis. Results reveal that the single-pulse rotation deployment strategy can fully deploy the net and maintain the net-shape without any closed-loop controller, and it dramatically increases the effective deployment distance of the net. The parameter sensitivity analyses provide a reference for the rapid deployment and continuous shape maintenance of the tethered-space net robot system.     

退火工艺对交叉轧制MB1镁合金组织及性能的影响

为解决镁合金塑性加工变形能力较差的问题,利用显微组织观察和力学性能测试方法,研究退火工艺对交叉轧制MB1合金组织和性能的影响。结果表明:晶粒一般随退火温度的升高和退火时间的延长,先细化后长大,且组织中的孪晶会消失;退火后,MB1合金抗拉强度下降,伸长率明显提高;在退火温度为330℃且退火时间为30 min的条件下性能最佳,此时合金抗拉强度为205 MPa,伸长率为24.1%。     

IVIG无反应川崎病的预测研究进展

川崎病多发病于 5岁以下的儿童，静脉免疫球蛋白 (Intravenous Immunoglobulin，IVIG) 无反应的川崎病患儿罹患心血管并发症风险明显增高，而早期识别IVIG无反应的川崎病患儿并予以积极治疗可有效改善其预后。本综述结合文献，对IVIG无反应川崎病的预测单项指标及预测模型进行总结，为川崎病患儿诊疗提供依据。