关系矩阵法在发动机执行机构故障检测中的应用

作为航空发动机控制系统的重要组成部分, 执行机构的故障检测与隔离目前尚缺少有效方法.本文提出了一种新颖的解决问题途径, 利用相互关系矩阵, 通过发动机输出与控制器指令计算执行机构输出的偏差, 可以达到检测、隔离多个执行机构故障的目的.数字仿真表明, 这一方法在航空发动机执行机构故障检测中, 具有较高的准确性.      

电致动聚合物致动器材料及放大结构综述

为满足航天应用的需要,本文对EAP材料研究情况和它们典型的压电致动器放大结构发展趋势进行了综述。首先比较了干湿EAP材料的特性,提出了应用中需要注意的一些问题;其次,以典型的压电致动器放大结构为例,分析了其优缺点,强调了一些新颖的概念。最后指出,为克服航天应用中EAP致动器力和行程的限制,需要根据实际应用从材料和放大结构两方面展开深入研究。     

电磁流体动力驱动流体搅拌混合器特性研究

对小型电磁流体动力搅拌混合器的特性进行了理论分析和实验研究.该小型电磁动力混合器由聚碳酸脂和黄铜采用常规机械加工方法加工而成.研究采用的流体为氯化钠水溶液.为了观察流体的搅拌混合运动,在流体中加入微量微细玻璃珠作为示踪粒子.采用显微观测及图像采集技术记录流体的搅拌混合过程,用数字图像处理技术对流体速度场进行分析.建立了搅拌混合器的理论模型,并对其动力特性进行了数值分析,理论结果与实验结果相吻合.该小型电磁动力混合器已应用于微管道流动的混合控制并可应用于其它微流体控制系统中.     

微等离子体转化二氧化碳发射光谱诊断

火星大气层的主要成分为二氧化碳,如果能够利用低温等离子体方法高效分解二氧化碳,使其转化为氧气和一氧化碳加以利用,可以大幅降低航天员生命保障相关载荷长途运输的成本,进一步提高生命保障能力.低温等离子体放电过程中会产生大量活性组分,可以在数百度温度下实现二氧化碳的高效解离,是具有很大潜力的二氧化碳解离与转化方式.设计了一种...     

Experimental study of an insert and its influence on churning losses in a high-speed electro-hydrostatic actuator pump of an aircraft

The speed of an Electro-Hydrostatic Actuator (EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in aircraft EHA systems. In order to reduce churning losses at high speeds, more attention should be given to the design of an insert. In this paper, the effect of an insert with different design parameters on churning losses is investigated through Computational Fluid Dynamics (CFD) simulation and experiments by calculating the difference between churning losses torques of the test pump with and without the insert based on a high-speed churning losses test rig. Analytical results show that the gap between the insert and the cylinder is critical for churning losses reduction. It is found that the churning losses of the test pump can be reduced with a decreasing gap between the cylinder block and the insert at high speeds. This is because the insert can decrease the turbulence occurrence at high speeds. The results can be used for flow field analysis and optimization of the high-speed EHA pump and provide a new method for improving efficiency of high-speed EHA pumps.     

谐振式微机械惯性传感器

对几种典型的谐振式加速度微传感器和微陀螺的结构、工作原理等方面进行了概述，分析了各自的应用特点。从中反映出谐振式微惯性传感器具有优良的特性，必有广阔的应用和发展前景。     

某型飞机空中飘摆故障分析及防护措施

分析某型飞机平尾助力器故障导致飞机在空中飞行时产生飘摆现象的原因,提出修理改进措施及维护对策。     

Active fault tolerant control for vertical tail damaged aircraft with dissimilar redundant actuation system

This paper proposes an active fault-tolerant control strategy for an aircraft with dissim-ilar redundant actuation system (DRAS) that has suffered from vertical tail damage. A damage degree coefficient based on the effective vertical tail area is introduced to parameterize the damaged flight dynamic model. The nonlinear relationship between the damage degree coefficient and the corresponding stability derivatives is considered. Furthermore, the performance degradation of new input channel with electro-hydrostatic actuator (EHA) is also taken into account in the dam-aged flight dynamic model. Based on the accurate damaged flight dynamic model, a composite method of linear quadratic regulator (LQR) integrating model reference adaptive control (MRAC) is proposed to reconfigure the fault-tolerant control law. The numerical simulation results validate the effectiveness of the proposed fault-tolerant control strategy with accurate flight dynamic model. The results also indicate that aircraft with DRAS has better fault-tolerant control ability than the traditional ones when the vertical tail suffers from serious damage.     

利用压电自敏感致动器的挠性结构振动主动控制实验研究

以粘贴有压电自敏感致动器的挠性梁振动主动控制为例，论述了进行挠性结构传感器／致动器及控制一体化研究的方法，文中给出了压电自敏感致动器的电路模型及自敏感感器 变测量和应变速度测量电路，推导了测量公式，以玻璃钢材料的挠性梁为实验对象，并采用自适应滤波技术来实现振动主动控制，控制系统由ＴＭＳ３２０Ｃ２５及４８６计算机组成的主从机系统来实现，实验结果表明此种控制方法是有效的。     

准LIGA技术的研究与发展

介绍近年来准ＬＩＧＡ技术发展的概况，着重讨论国内外对它的各个工艺过程所采取的一些措施及其在微传感器和微执行器中的应用，并简单论述它的发展趋势。