卫星姿态的模糊控制研究与物理仿真

随着空间技术的发展,现代卫星的姿态控制面临着挠性附件对本体姿态的耦合作用,精确的数学模型越来越难以建立.采用模糊控制的方法,用动量飞轮作为执行机构,对卫星的姿态控制进行了单轴物理仿真,与传统控制方法相比模糊控制更适用于非线性大延迟系统,可使卫星姿态在参数交化与外部干扰情况下具有较好的姿态稳定度与精度.  

基于参数BP网络的自整定PID控制在柔性结构控制中的应用

针对大射电望远镜(LT)悬索粗调系统为一非线性慢时变大滞后柔性系统的特点,提出用参数BP神经网络自整定PID控制器来实现馈源轨迹跟踪策略.仿真研究表明,该控制算法可以很好地满足馈源系统轨迹跟踪高精度要求.  

基于压电材料的引线键合微夹持器设计

引线微夹持器是IC/LED键合系统的关键模块.该文综合采用压电智能材料与柔性联接的组合结构,设计了键合系统的引线微夹持器.利用有限元法,计算了微夹持器的振动模态与静力特性,获得了系统的固有频率、振动模态及电信号驱动下的支臂端部张开量.在实验上,通过高速摄像系统的跟踪实验,捕获了系统支臂端部的运动行为,获得了系统张开量与驱动电压的关系;并用激光非接触测量技术,获得系统端部的振动特性.该文计算与实验均为引线微夹持器的可靠性应用提供基础.  

In-cell adaptive touch technology for a flexible e-paper display

In-cell adaptive touch technology for use in an electrophoretic display (EPD) has been developed and implemented in 11.5 in. UXGA flexible electronic paper display. Here, two types of a-Si:H photo-sensor arrays fabricated on a stainless steel substrate at the process temperature of 250 °C have been used along with an overall capacitive sensor formed on top of the flexible panel. Thus, we can resolve the sensing issue of normal photo-sensor array as well as maintain the feature of low power consumption in the EPD. Moreover, new touch algorithm adapted depending upon the amount of light intensity has been applied to enhance touch sensitivity regardless of environmental light conditions.  

Generator speed regulation in the presence of structural modes through adaptive control using residual mode filters

Wind turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, potentially causing component fatigue and failure. Two key technology drivers for turbine manufacturers are increasing turbine up time and reducing maintenance costs. Since the trend in wind turbine design is towards larger, more flexible turbines with lower frequency structural modes, manufacturers will want to develop control paradigms that properly account for the presence of these modes. Accurate models of the dynamic characteristics of new wind turbines are often not available due to the complexity and expense of the modeling task, making wind turbines ideally suited to adaptive control approaches. In this paper, we develop theory for adaptive control with rejection of disturbances in the presence of modes that inhibit the controller. A residual mode filter is introduced to accommodate these modes and restore important properties to the adaptively controlled plant. This theory is then applied to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine. The adaptive pitch controller is compared in simulations with a baseline classical proportional integrator (PI) collective pitch controller.  

小型反射镜周边支撑技术

从满足空间光学遥感器反射镜在复杂的工况下综合面形误差要求的角度出发，介绍了小型凸非球面反射镜材料及支撑方式的选择；根据反射镜的定位原理进行反射镜支撑结构的设计；采用CAD/CAE工程分析软件从支撑结构的材料及支撑方式进行分析和优化，设计一种有效的反射镜周边支撑结构，使反射镜面形误差变化量PV值小于λ/10，RMS值小于λ/50（λ=632.8 nm）。最后，测试反射镜在力学环境试验前后的面形变化，证明该结构满足设计要求。  

柔性结构技术在精密工件台中的应用

通常,在半导体设备刚性结构设计中要求零部件有很高的加工制造精度和装配精度,同时易传递振动、热等,并容易引入附加的力和转矩。为降低质量和成本,并提高工作性能,目前在工件台的设计中广泛采用柔性结构设计技术。列举了常见柔性件结构形式,并分析了不同结构形式柔性件的旋转刚度和精度等特性。同时,根据工件台的实际工作状态和性能需求,选取适用的柔性件结构形式,并结合弹性静力学的理论公式,进行工件台中常用柔性件设计和计算。