Robust fuzzy controlled photovoltaic power inverter with Taguchi method

This paper presents design and implementation of a robust fuzzy controlled photovoltaic (PV) power inverter with Taguchi tuned scaling factors. To achieve fast transient response, small steady-state error and system robustness, a robust fuzzy controller is adopted, in which its input and output scaling factors are determined efficiently by using the Taguchi-tuning algorithm. The proposed system can operate in different modes, grid-connection mode and stand-alone mode, and can accommodate wide load variations. Simulation results and hardware measurements obtained from a prototype with a microcontroller (Intel 80196KC) are presented to verify the theoretical discussions, and its adaptivity, robustness and feasibility.     

基于交互正交试验的空间用谐波减速器传动性能影响因素研究

 针对空间用谐波减速器的传动性能受多种因素影响且这些因素又相互作用的实际情况,选用XB1-60-150型谐波减速器,采用交互正交试验方法,进行了谐波减速器传动性能热真空试验,考察了转速、环境温度、负载扭矩和润滑方式等因素及其耦合作用对谐波减速器传动效率的影响.通过极差分析和方差分析研究了各因素及其耦合作用对传动效率的影响敏感性,两种分析方法得到的试验结果一致.结果表明,在置信度p=99%时,转速和环境温度对谐波减速器传动性能有显著影响,且负载扭矩与润滑方式之间的交互作用高度显著;交互作用分析获得了谐波减速器最佳的空间使用条件,在该条件下谐波减速器的传动性能最优.     

障碍地形下的机器人轮足复合越障步态规划方法

为提高轮足复合机器人在障碍地形下的稳定性与通行效率,提出了一种轮足复合越障步态规划方法。首先基于轮足复合运动模式提出了一种机器人位姿调整算法,并给出了相应的足端轨迹方程与重心轨迹方程。其次基于轮足复合运动的运动学方程,给出了位姿调整阶段的轮速规划算法,使得每条腿足端轮子的滚动速度与足端的轨迹相匹配,以确保轮子在地面滚动时不发生滑动。虚拟样机仿真结果表明,应用该步态规划算法,机器人能够自主平稳地穿越障碍地形,从而验证了方法的有效性。     

基于改进A~*算法的进离场航线网络3D规划

为提高终端空域航线设计的自动化水平,对进离场航线进行了研究。针对独立航线规划,提出角度扩展航路点搜索方法,提高算法运行效率。选取水平剖面经济性最优为目标函数,垂直剖面满足最优爬升/下降剖面,实现3D航线网络规划。实例结果表明,在保证航线安全性、经济性的同时,算法运行稳定,效率明显提高。     

基于三维参数化模型构建的飞机重量重心快速估算方法

 针对飞机总体设计阶段重量重心(c.g.)估算的专业要求、设计方案反复调整的特点,提出了基于三维参数化建模的重量重心快速估算方法,从而实现后续的快速参数化调整。基于该方法的分析流程,通过分析飞机外形建模和结构、系统重量建模的工作对象和专业逻辑,对各个重量组成及其建模过程进行了参数化描述和流程定义,用于指导完成整个设计分析系统的开发实现。最后,通过算例演示了基于三维参数化建模进行重量重心快速估算的步骤。     

Aerodynamic/Stealthy/Structural Multidisciplinary Design Optimization of Unmanned Combat Air Vehicle

An optimization strategy is proposed to deal with the aerodynamic/stealthy/structural multidisciplinary design optimization (MDO) issue of unmanned combat air vehicle (UCAV). In applying the strategy, the MDO process is divided into two levels, i.e. system level optimization and subsystem level optimization. The system level optimization is to achieve optimized system objective (or multi-objective) through the adjustment of global external configuration design variables. The subsystem level optimization consists of the aerodynamic/stealthy integrated design and the structural optimization. The aerodynamic/stealthy integrated design aims at achieving the minimum aerodynamic drag coefficient under the constraint of stealthy requirement through the adjustment of local external configuration design variables. The structural optimization is to minimize the structural weight by adjusting the dimensions of structural components. A flowchart to implement this strategy is presented. The MDO for a flying-wing configuration of UCAV is employed to illustrate the detailed process of the optimization. The results indicate that the overall process of the surrogate-based two-level optimization strategy can be implemented automatically, and quite reasonable results are obtained.     

飞行器参数化几何建模方法研究

高超声速飞行器的概念设计阶段通常要综合考虑气动力、气动热、飞行弹道、推进系统、结构和控制等多个学科的设计因素,希望通过权衡各个学科得到一个综合性能最佳的设计,即多学科设计优化结果.参数化几何建模是优化设计的基础,本文开展飞行器参数化几何建模的方法研究,利用二次曲线方法与基于类型函数和形状函数的方法,分别进行了两种飞行器几何外形的建模,并进行了初步的气动力计算.通过分析两种建模方法的特点,比较了两种方法在不同情况下的优缺点,提出了在飞行器概念设计阶段几何建模方法的一般选取建议.通过等弧度、等弧长的划分原则,完善了基于类型函数和形状函数方法所生成的表面网格质量.     

航空惯性稳定装置的齿隙误差实验平台设计

设计了航空惯性稳定装置的齿隙误差实验平台。该平台通过更换不同尺寸的齿轮和调节齿轮中心距,实现齿隙微调,用于研究不同传动比和不同齿隙情况下的齿隙误差特性,为航空惯性稳定装置的齿隙误差建模与补偿工作奠定了基础。     

数控机床校准周期的合理确定

从具体实际出发，充分分析影响机床最终加工精度的诸多因素，应用田口方法科学合理地确定数控机床的最佳校准周期，保障机床加工过程的质量控制。     

基于流场感知的小型飞行器姿态控制

小型飞行器由于外形尺寸等限制很难实现理想的姿态控制，而自然界中的鸟类却可以完成高质量的飞行，原因是它们能够获得自身周围的气流信息。受这些自然现象的启发，设计了一个基于流场感知的小型飞行器姿态控制系统。通过流场感知的气流信息（压力和剪应力）可以计算出气动力和力矩。建立了一种小型飞行器的非线性三轴姿态动力学模型，将力矩信息引入姿态运动，然后利用非线性模型预测控制来设计姿态控制器。与传统的控制方法相比，这种新型控制方法不需要从气动实验获得的先验信息，所用的参数都是由在线测量得到的数据计算得出的，因此能及时感知外界环境变化并减少响应时间。仿真结果表明，该控制方法可以提高小型飞行器在复杂流场环境下姿态控制系统的性能。     

An optimal method of posture adjustment in aircraft fuselage joining assembly with engineering constraints

Posture of an aircraft fuselage can be evaluated based on the coordinate values of measure points fixed on the aircraft fuselage in aircraft final assembly. Posture adjustment is carried out by rotation and translation of the aircraft fuselage to make sure that the actual coordinate values of the measure points are coincided with the theoretical ones read from the computer aided design(CAD) model. The point registration method of posture adjustment without considering engineering constraints may cause out-of-tolerance for some engineering constraints. Hence, engineering constraints such as plane symmetry of two points, as well as coplanar and collinear of the multipoint should be considered in the new optimal method of posture adjustment in aircraft fuselage joining assembly. Based on the point registration model, a multi-objective optimization model of posture adjustment considering engineering constraints including collinear, coplanar, and symmetry constraints is established and represented by a uniform vector function. The weights of constraint conditions can be set freely in the optimization model to reflect the importance of the corresponding constraints in aircraft fuselage joining assembly. The rotation and translation parameters of posture adjustment are obtained by the proposed multi-objective optimization algorithm based on the Gauss-Newton method. Results of an example of aircraft fuselage joining assembly show that constraint errors of posture adjustment obtained by the multi-objective optimization model are not out of tolerance for design constraint errors and satisfy the requirement of aircraft fuselage joining assembly.     

基于回路整型设计的多轴振动控制

 多激励多轴向振动控制试验中,在频响函数矩阵呈现病态的频率点,控制点响应的自谱和互谱往往难以达到预定参考谱目标。针对这种情况,首先在控制频段对频响函数进行拟合修正,求得系统前置补偿矩阵,然后根据 H_∞回路整型理论对驱动谱矩阵进行整型,将整型后的驱动谱矩阵代替原驱动谱进入控制回路计算。通过试验验证表明,基于回路整型设计的修正算法,能够明显地抑制某些频段内频响函数的不良影响,自谱和互谱响应都能得到比较理想的控制结果。     

发动机的涡轮导向器面积、喷口直径等匹配参数调整的计算方法研究和应用

在双轴式涡轮喷气发动机中 , 及 级涡轮导向器面积和尾喷口面积匹配关系影响到发动机工作稳定性、可靠性和性能。本文用计算分析方法进行了研究 ,推导出便于编程计算的 6个方程 ,用低压涡轮功等于某一常数代替低压转子转速为常数的调节方案 ,并用发动机台架实测参数确定部件某些系数 ,计算仅在设计转速上进行。计算结果指导了某新研发动机三面积的调整 ,获得合适的三面积调整范围 ,解决了该发动机的调整参数匹配问题 ,按本方案调整的发动机经外场使用表明工作稳定、可靠     

粉末高温合金盘件预成形设计的类等势场分析法(英文)

传统的预成形设计方法精度低、耗时、耗力,为了克服这些缺点,提高产品的质量和工作效率并降低生产成本,需对预制坯进行合理的预成形设计。本文根据能量最小原理和最小阻力原理,利用塑性变形过程中坯料的流动规律于静电场等势线分布类似这一特性,提出一种能够进行预成形设计的新方法-类等势场法,并采用该方法对粉末高温合金盘件进行预成形设计,从中优选出6组预成形形状,利用MSC/Superform商用软件对上述预制坯的等温成形过程进行数值模拟,得到6组粉末高温合金盘件终锻结束时各个部分的等效应变分布、预锻和终锻的变形程度分配以及模具型腔的受力情况。通过分析,选出最佳的设计方案。     

A Systematic Approach to Blind-Speed Elimination

In radars that achieve a high subclutter visibility by coherent processing over several pulses, a serious problem appears in the form of blind Dopplers, or ?speeds,? at which target detection is impossible. Of the possible methods of eliminating these blind speeds, the most basic one that is employed when the performance requirements are high involves the use of several PRF's. These PRF's are chosen so that coverage is obtained at any Doppler with at least one PRF. The problem faced by the radar designer is to select the set of PRF's and the pulse numbers for each PRF so that the search frame time is minimized. This paper evolves a systematic method for the design of the blind-speed elimination scheme. A formalized approach is offered that shows the possible combinations of wavelength, PRF, and pulse number and the tradeoffs involved, without introducing the confusion ordinarily associated with multiparameter choices.     

可调叶片运动机构的参数化拓扑仿真模型研究

介绍1种在方案设计阶段,基于UG NX的3维设计软件和EXCEL软件的压气机多级静子叶片联调操纵机构的联合设计方法。通过在UG软件的建模模块中构建简单的线条以建立操纵机构的拓扑模型,并将模型输入运动仿真模块中,对整套机构进行运动学仿真计算,跟踪各级传动关节的运动规律,得到仿真数据。将仿真数据在EXCEL软件中进行分析,综合拟合、回归、关联度等数据分析手段,得到特定拓扑模型下的输出规律。在方案设计阶段即可快速建立机构模型并分析影响整套机构运动规律的关键参数,优化设计参数、建立操纵机构调节方程,给后期的工程设计提供基础。经某型燃气轮机多级联调机构的设计实践证明,该方法具有高效敏捷,适应面宽,可借鉴性强的特点。     

多目标进化算法和代理模型技术在气动稳健优化设计中的应用

通过与传统优化方法的优缺点对比,提出针对飞行器环境参数存在不确定性影响时的气动稳健优化设计模型,并应用多目标进化算法和代理模型技术对稳健模型进行优化设计研究。提供了翼型稳健性优化实例,通过选择合适的翼型参数化方法和CFD求解程序以及不确定性分析方法,得到了稳健设计结果的Pareto前缘图。从其中选择的设计结果可以看出,稳健设计结果表现出更稳定的特性,证明了稳健设计的优势所在。     

平台稳定回路模糊PI参数在线调整控制

平台系统稳定回路依靠对外环、内环和台体的控制使平台台体在各种干扰力矩作用下都能提供精确的惯性导航基准,保证平台系统精度。针对目前回路控制超调量较大的问题,提出一种模糊PI参数在线调整的抗干扰控制方法,经过仿真表明在保证稳定回路快速调节的基础上,稳定回路动态特性得到了改善。该方法对今后新型平台系统伺服回路控制系统设计的进一步提高提供了一定指导作用。     

Minimax Approach to Trajectory Optimization of Multistage Launch Vehicles

An optimum pitch steering program is developed, using a minimax technique, for a multistage launch vehicle in the presence of large parameter uncertainties. The uncertainties are characterized by deterministic bounds on the respective parameters. The pitch steering program is obtained by maximizing two independent scalar performance ance indexes. 1) the coast apogee velocity for a specified altitude; 2) the perigee of the satellite orbit. The product of dynamic pressure and angle of attack is constrained so as to minimize the structural loads during the atmospheric flight. The values of the uncertain parameters are determined by minimizing the same performance indexes in order to achieve a worst case design. The existence of saddle point solution to this class of problems is shown using the techniques of differential game theory. The conjugate gradient algorithm has been used for computer er aided design of the minimax technique.     

设计特征模型中的加工特征识别

当特征设计方法产生的模型中存在正特征或出现特征相关时,则无法直接得到加工特征。提出设计特征模型中的加工特征识别算法,即：工艺毛坯与设计特征模型的差得到零件加工区域,设计特征的规则化处理得到规则化设计特征模型,利用它可以从零件加工区域中逐步分解出所有的加工特征。