LVDS技术分析和应用设计

低压差分信号(Low Voltage Differential Signaling,LVDS)是一种低压摆幅的差分信号技术,具有更高的比特率,更低的功耗,更好的噪声性能和更稳定的可靠性.分析了LVDS的技术原理和优势所在;讨论了在高速电子系统设计中应用LVDS时,对于印刷电路板(Printed Circuit     

PB中动态数据窗口的使用

通过对数据窗口控件、数据窗口对象以及如何利用SyntaxFromSQL ()函数生成符合数据窗口对象语法的字符串的介绍 ,详细说明了动态数据窗口在PowerBuilder中的用法     

多晶体γ探测器相互影响的蒙特卡洛数值模拟

本文用基于Geant4的蒙特卡洛方法模拟得到多晶体航空γ能谱仪对近似无限大γ面源的能量沉积谱,分析了航空γ能谱仪各条晶体的谱线差异,并研究了不同能量的地面γ辐射在上层晶体中形成谱线的变化规律,以及对环境氡气校正的影响,为多晶体航空γ能谱测量谱线解析提供了理论基础。     

提高金回收率的试验研究与生产实践

胶东某矿业公司矿石中金以细粒包裹金为主,泥质矿物含量较高。多年来,金的回收率较低。针对矿石性质,进行了磨矿细度(粗选尾矿再磨)、改善药剂制度等试验研究与生产实践,金的回收率提高了3.63%,企业每年可增加经济效益300余万元。     

Robust adaptive active fault‐tolerant control of UAH with unknown disturbances and actuator faults

This paper proposes a robust active fault‐tolerant control (AFTC) approach for medium‐scale unmanned autonomous helicopter (UAH) with rotor flapping dynamics in the presence of unknown external disturbances and actuator faults. The robust items are adopted to improve the disturbance rejection capability of the UAH system. The adaptive fault observers are developed to estimate the fault parameters and the fault detection (FD) algorithms are presented to detect the actuator faults in different loops. In order to obtain satisfactory trajectory tracking performance, a backstepping‐based robust AFTC scheme is designed for the simplified 6‐degree‐of‐freedom (DOF) UAH nonlinear dynamics model and the global stability of the closed‐loop system is proved by using the Lyapunov method. Several groups of numerical simulation results are carried out to verify the effectiveness of the developed method.     

分段寻优混沌扩频降低车载LLC谐振变换器电磁干扰

车载电子测量设备由于电磁干扰会产生误动作或失灵现象,传统混沌扩频可以从源头上降低车载LLC谐振变换器的电磁干扰,但随着扩频宽度的增加会造成输出电压纹波增大、效率降低问题。基于此,首先通过网格多涡卷蔡氏系统生成混沌序列,以向左扩频的方式实现了混沌扩频。其次提出以电磁干扰抑制量变化率以及扩频宽度变化率为判据的分段遍历寻优算法,结合带高频寄生参数的传导干扰预测模型,对国标规定不同频段进行扩频宽度的寻优,根据寻优结果提出了差、共模干扰的分段最优扩频宽度调制策略。最后仿真与实验结果能验证所提出的策略能实现最大707 dB电磁干扰降低,减少最大615%输出电压纹波,并实现电路效率的提升。     

Risk‐sensitive filtering for nonlinear Markov jump systems on the basis of particle approximation

In this paper, the risk‐sensitive filtering method that relaxes the dependence on model accuracy is extended to nonlinear Markov jump systems (MJSs). In the method, the so‐called reference probability technique together with particle approximation is utilized to derive the risk‐sensitive filter in nonlinear non‐Gaussian framework. The novelty of the proposed approach is that a ‘risky’ interacting resampling step is performed to both moderate the modeling uncertainties and to solve the problem of particle explosion. A designer‐chosen parameter named risk‐sensitive parameter allows us to make a trade‐off between the filtering accuracy for the nominal model and the robustness to uncertainties. With a meaningful example, it shows that the developed method can outperform the widely used method‐particle filter and interacting multiple model‐particle filter in nonlinear MJSs with uncertainties. Copyright © 2011 John Wiley & Sons, Ltd.     

LLE-based classification algorithm for MMW radar target recognition

In this paper, a new multiclass classification algorithm is proposed based on the idea of Locally Linear Embedding (LLE), to avoid the defect of traditional manifold learning algorithms, which can not deal with new sample points. The algorithm defines an error as a criterion by computing a sample’s reconstruc-tion weight using LLE. Furthermore, the existence and characteristics of low dimensional manifold in range-profile time-frequency information are explored using manifold learning algorithm, aiming at the problem of target recognition about high range resolution MilliMeter-Wave (MMW) radar. The new algo-rithm is applied to radar target recognition. The experiment results show the algorithm is efficient. Com-pared with other classification algorithms, our method improves the recognition precision and the result is not sensitive to input parameters.     

色温和光通量独立可调的白光LED系统

介绍了一种色温和输出光通量独立可调的白光LED系统。该系统不仅实现了色温的连续可调,同时还具有输出光通量独立调节的优点。在介绍了混光的理论基础之外,还包含了色温和输出光通量独立可调的实现方法以及白光LED测试的数据。     

砂轮平衡精度的最小二乘测试计算法

提出一种测算砂轮不平衡精度的最小二乘新方法 ,给出基本原理和具体算法 .该方法能有效抑制测量误差的影响 ,大大提高测试精度 ;并能同时测出残余不平衡量的大小和相位 .可用于各类平衡器的精度测定