超分辨条件下雷达目标散射点数的估计方法

为了在状态空间超分辨理论的框架下获得雷达目标散射点数目的估计,本文提出了一种基于状态空间理论的雷达高频区目标散射点数判定准则,该方法利用信号与噪声子空间的正交性质,搜索最优的散射点数目,理论分析与仿真试验均证明了该方法的正确性.     

A METHOD FOR GENERATING INDEPENDENT REALIZATIONS OF A MULTIVARIATE NORMAL STATIONARY AND INVERTIBLE ARMA(p, q) PROCESS

Abstract. A method for generating finite independent realizations of a normal multivariate stationary ARMA( p, q ) process is proposed. It is based on an AR (1) representation of an ARMA( p, q ) process allowing for an exact generation of the initial values of the simulation algorithm. Input facilities are supplied in order to assure stationarity and invertibility of the considered process.     

基于方向变换矩阵的三维装配草图生成方法

针对求解方案设计获得的可行方案的空间布局及可视化表达问题，提出了三维装配草图的一种自上而下设计方法，建立了方向变换矩阵，并通过其分解描述子装配体在空间的布局。基于三维实体造型平台，提出了相应的算法加以实现。通过一个设计实例验证该生成方法及算法可行、有效。     

基于状态空间平均法的单相逆变器控制建模

论述了状态空间平均法的实质和一般步骤，应用状态空间平均法引出了一种线性时不变的、与负载扰动不相关的单相逆变器控制模型，指出了所得到的模型及其变种的用法特点。为验证状态空间平均模型的准确性。在一台单相全桥逆变器上进行了实验。实验表明，所得状态空间平均模型的精确性和可用性可以满足要求。     

改进型混合悬浮系统线性控制方法的研究

悬浮控制技术是磁悬浮技术中的核心和关键,其性能的好坏,将直接影响到磁浮系统的稳定性、安全性。在一般线性控制方法的基础上进行了改进。利用简化的混合单电磁铁的动态模型得出数学模型,而后在一般控制方法基础上得出以电流作为控制输入变量的控制模型。通过对2种控制模型的仿真分析,进一步验证了改进后的控制策略的优越性。     

扩展状态平均法在单级PFC变换器的应用研究

将扩展状态平均法理论应用到单级功率因数校正(Power Factor Correction,简称PFC)变换器的研究中.建立了带抽头电感的PFC变换器的等效电路模型,并推导出反映电路主要特性的状态方程式.用解析建模法建立了Matlab仿真模型,并对电路参数进行了优化,通过实验验证了解析方法的正确性.     

Controller Design Using Ant Colony Algorithm for a Non-inverting Buck–Boost Chopper Based on a Detailed Average Model

In this article, the non-inverting buck–boost converter and its operation modes are scrutinized. The closed-loop stability of the converter in buck and boost modes is analyzed, and the necessity of using an appropriated controller is demonstrated. Then the application of an adapted ant colony optimization to design a feedback controller is proposed, and a controller based on its existing model is tuned. Simulation and experimental results obtained from the ant colony optimization designed controller are then compared with a controller designed with the classic method. Although the simulation and experimental results prove the efficiency of the proposed control approach, a significant difference between controller behavior in practice and simulation is obvious. Finding these differences, more detailed models, including all parasitic elements, in the buck and boost modes are derived. Applying the proposed model in controller design illustrates that the desired performance of the converter can be guaranteed with a simple proportional-integral (PI) controller. The suggested ant colony-based controller is again tuned based on the more detailed model, which improves the performance of the converter system even more. Furthermore, good agreement between analytical and experimental outputs validates the accuracy of the modeling and simulation.     

基于状态空间法的架空输电线路的可靠性评估

本文运用马尔柯夫理论建立了一种考虑天气影响的架空输电线路可靠性评估数学模型。该模型将输电线路的运行状态划分为四种状态,给出了每种平稳状态的状态概率、状态频率和状态持续时间的计算方法。实例分析验证了本文提出的模型及算法的正确性。