水平导航中转弯航线解算方法的研究和仿真

在飞机显示器的水平导航区域上需要为飞行员实时显示最新的航线信息，航线中的每个航路点均有不同的转弯方式，目前国内正在研发的飞机采用旁切转弯和飞越转弯两种方式，若错过了预计的转弯起始点，则需要重新进行航线解算，这被定义为超调转弯，给出三类转弯航线的解算方法。     

Rotation Control of a 3-DOF Parallel Mechanism Driven by Pneumatic Muscle Actuators

The pneumatic muscle actuator(PMA) has many advantages,such as good flexibility,high power/weight ratio,but its nonlinearity makes it difficult to build a static mathematical model with high precision. A new method is proposed to establish the model of PMA. The concept of hybrid elastic modulus which is related to the static characteristic of PMA is put forward,and the energy conservation law is used to achieve the expression of the hybrid elastic modulus,which can be fitted out based on experimental data,and the model of PMA can be derived from this expression. At the same time,a 3-DOF parallel mechanism(a new bionic shoulder joint)driven by five PMAs is designed. This bionic shoulder joint adopts the structure of two antagonistic PMAs actualizing a rotation control and three PMAs controlling another two rotations to get better rotation characteristics. The kinematic and dynamic characteristics of the mechanism are analyzed and a new static model of PMA is used to control it.Experimental results demonstrate the effectiveness of this new static model.     

针对旋翼流场模拟的自适应网格算法

针对基于格心格式求解器的旋翼流场模拟,提出了相应的自适应笛卡尔网格的数据存储结构及自适应算法。给出了相应的单元处理策略,简化了对自适应笛卡尔网格的处理;对于频繁的自适应加密过程中产生的大量重复点,采用了高效的交替数字树算法(Alternating digital tree,ADT)予以删除;对于自适应疏化过程中产生的大量无用点,提出了标记-删除-移动(Mark,delete,move,MDM)算法予以快速地删除,减少了不必要的计算资源消耗。对CaradonnaTung旋翼在不同悬停状态下进行了模拟验证,对比了压力分布系数与桨尖涡位置。之后对HELISHAPE 7A旋翼在前飞情况下进行了模拟验证,计算值与实验值吻合。此外,求解器对桨尖涡的捕捉效果得到了明显的提高,表明本文方法具有良好的有效性与鲁棒性。     

基于波长控制的光纤陀螺标度因数温度性能提高方法

光纤陀螺的标度因数与光纤环的长度、直径及光源的平均波长有关。在温度条件下，光纤环的长度、直径及光源的平均波长均会发生变化，进而导致光纤陀螺在高低温下的标度因数不同，影响温度环境下的光纤陀螺标度因数的重复性。提出了一种基于光纤陀螺波长控制的标度因数温度性能提高方法，该方法在光源驱动电路的桥式回路中增加了铂电阻组件，从而可自动调节光纤陀螺光源的管芯温度，进而控制光源平均波长的变化，以抵消光纤环有效面积因温度变化而对标度因数产生的影响，提高温度环境下光纤陀螺的标度因数重复性。试验表明，该方法将未补偿情况下光纤陀螺全温范围内的标度因数重复性(1σ)由271×10-6~280×10-6减小到了32.5×10-6~43.5×10-6，标度因数重复性误差减小了84%~88%，并验证了该方法的有效性。     

Multi-level virtual prototyping of electromechanical actuation system for more electric aircraft

Electromechanical actuators (EMAs) are becoming increasingly attractive in the field of more electric aircraft because of their outstanding benefits, which include reduced fuel burn and maintenance cost, enhanced system flexibility, and improved management of fault detection and isolation. However, electromechanical actuation raises specific issues when being used for safety-critical aerospace applications like flight controls: huge reflected inertia to load, jamming-type failure, and increase of backlash with service due to wear and local dissipation of heat losses for thermal balance. This study proposes an incremental approach for virtual prototyping of EMAs. It is driven by a model-based system engineering process in order to enable simulation-aided design. Best practices supported by Bond graph formalism are suggested to develop a model’s structure efficiently and to make the model ready for use (or extension) by addressing the above mentioned issues. Physical effects are progressively introduced, and the realism of lumped-parameter models is increased step-by-step. In particular, multi-level component models are architected to ensure continuity between engineering activities. The models are implemented in the AMESim simulation environment, and simulation responses are given to illustrate how they can be used for preliminary sizing, control design, thermal balance verification, and faults to failure analysis. The proposed best practices intend to provide engineers with fast, reusable, and efficient means to assess performance virtually and enhance maturity, performance, and robustness.     

轮胎和缓冲支柱压力对摆振特性的影响

阐述了摆振分析的基本思路,分析了轮胎和缓冲支柱压力对摆振特性的影响,并结合某起落架计算比较了不同轮胎及缓冲支柱压力下的摆振特性。研究表明:当两者压力降低时,摆振临界阻尼均减小,有利于防摆;反之,摆振临界阻尼均增大,不利于防摆;但在两者压力变化的百分比相同的情况下,轮胎压力变化比缓冲支柱压力变化对摆振特性的影响更明显。     

Orbit determination and prediction of GEO satellite of BeiDou during repositioning maneuver

In order to establish a continuous GEO satellite orbit during repositioning maneuvers, a suitable maneuver force model has been established associated with an optimal orbit determination method and strategy. A continuous increasing acceleration is established by constructing a constant force that is equivalent to the pulse force, with the mass of the satellite decreasing throughout maneuver. This acceleration can be added to other accelerations, such as solar radiation, to obtain the continuous acceleration of the satellite. The orbit determination method and strategy are illuminated, with subsequent assessment of the orbit being determined and predicted accordingly. The orbit of the GEO satellite during repositioning maneuver can be determined and predicted by using C-Band pseudo-range observations of the BeiDou GEO satellite with COSPAR ID 2010-001A in 2011 and 2012. The results indicate that observations before maneuver do affect orbit determination and prediction, and should therefore be selected appropriately. A more precise orbit and prediction can be obtained compared to common short arc methods when observations starting 1 day prior the maneuver and 2 h after the maneuver are adopted in POD (Precise Orbit Determination). The achieved URE (User Range Error) under non-consideration of satellite clock errors is better than 2 m within the first 2 h after maneuver, and less than 3 m for further 2 h of orbit prediction.     

MEMS惯测技术在管道测绘系统中的应用

针对小口径管道的测绘问题,提出了一种MEMS惯测装置在小管道测绘系统中应用的方法,直接利用地标点信息为MEMS惯测装置装订初始方位,采用因子图理论对惯性/里程计组合导航信息进行处理,通过后续处理对装订误差进行修正,解决了MEMS惯测装置无法完成初始对准的问题。给出了惯性/里程计组合导航的因子图以及和积算法递推公式,并通过牵引试验对所提方法进行了验证。试验结果表明,提出的应用方法能够有效解决小口径管道的测绘问题,在100m间隔的路标点条件下,单边定位精度能够达到5cm。     

CFRP反射器型面主动控制和作动器位置优化

研究了运用压电陶瓷作动器对碳纤维增强复合材料（CFRP）格栅反射器的型面主动控制。首先，采用了一种具有独立电压自由度的梁单元，以及考虑高阶剪切变形的板单元，对主控格栅反射器进行有限元建模；运用能量变分哈密尔顿原理推导了主控格栅反射器的有限元控制方程，并给出了反射面型面残余均方根（RMS）误差最小的电压最优控制方法。然后，研究了在典型载荷下，反射面残余RMS误差最小的PZT作动器位置分布的优化配置问题；提出了一种将遗传算法和梯度投影方法相结合的改进优化方法，用来求出在限定作动器数量的条件下，作动器几何位置的优化配置，使控制后反射面的残余RMS误差最小；给出的数值算例验证了方法的正确性和有效性。最后，研制了格栅反射器型面主动控制的实验样机，针对反射器的初始制造误差进行了型面主动控制，验证了控制方法的可行性和有效性。     

永磁同步电机驱动太阳翼扰动力矩建模与仿真

建立太阳翼驱动机构(SADA)永磁同步电机的电磁方程，并利用固定界面模态综合法建立SADA驱动太阳翼耦合系统的振动方程；设计模拟柔性负载，对SADA驱动该柔性负载的扰振力矩进行仿真分析。结果表明，SADA驱动柔性负载运行过程中所产生扰振力矩主要由两个原因引起：1)电流噪声引起的力矩波动；2)控制参数选取不当引起的转角波动。