模拟朗缪尔探针伏安特性的非线性电子负载的设计与样机研制

研发了一套模拟朗缪尔探针伏安特性的非线性电子负载,由载波相移正弦脉宽调制(CPS-SPWM)技术的级联型H桥变流器与双向DC/DC变换器两部分组成.通过对电子负载设计方案开展建模仿真验证及样机初步测试表明,该系统基本达到了预期要求,可用于探针电源相关参数的测试及探针后端电子学系统的联合调试.     

Analysis and optimization of coupling to external cavities in feedback experiments with vertical-cavity surface-emitting lasers

The feedback strength is a crucial parameter for feedback experiments using semiconductor lasers. In this article, the coupling efficiency of the field of vertical-cavity surface-emitting lasers (VCSELs) to external cavities containing one collimating lens has been analyzed in detail using ABCD-matrix methods. It is found that for a given set of parameters there are two distinct, experimentally realizable positions of the collimating lens which allow for optimal coupling, if the cavity length is sufficiently small. The predictions are verified in experiments using single-transverse-mode VCSELs. The obtained coupling efficiencies exceed 70%.     

具有Neumann边界的抛物型方程组的反馈能稳性

该文研究了一类半线性抛物型方程组平衡解的有限维反馈能稳性, 控制器由对应于平衡解的线性化系统的LQ问题所导出. 该文发现在受控系统中如何施加控制是与平衡解有关的, 对于不同的平衡解, 在受控系统中应施加不同的控制.     

HL-2A装置等离子体水平位移控制

介绍了HL-2A装置等离子体水平位移反馈控制系统的硬件组成、控制流程和控制算法,反馈控制的调试过程。在相同参数放电条件下比较了等离子体位移的受控情况。等离子体位移的控制结果较为满意。     

Balancing singular discrete-time systems

In this work, we deal with normalizable-balanced singular systems, that is, singular systems where the obtained closed-loop system is balanced by an appropriate feedback. In the invariant case, we use a proportional and derivative feedback to obtain systems without infinite poles. In addition, the existence and construction of state-feedbacks to obtain normalizable-balanced N-periodic singular systems is analyzed.     

基于补偿网络的PSM高压电源模块仿真分析

利用MATLAB对中国聚变工程实验堆(CFETR)低混杂波高压电源系统的调节模块进行仿真,分析了静态电网波动、负载变化、滤波参数等对输出电压的影响。利用补偿网络可以大大减少纹波,增加输出电压的稳定性。该系统的稳定时间在几个毫秒之内,纹波系数<1%。通过仿真决定对该高压电源系统调节模块采用比例积分微分(PID)控制与超前-滞后补偿策略。     

一种频域合成房间频率响应的人工混响方法

给出了一种频域合成房间频率响应的方法用于卷积法人工混响,基于频域内房间频率响应的后期部分为高斯随机过程的假设,用自回归滑动平均模型为其自协方差函数和功率谱密度进行参数化描述,在对自回归滑动平均模型中的参数求解后,通过逆滤波得到了房间频率响应后期部分,与房间频率响应前期部分组合后经过傅里叶反变换得到完整的房间脉冲响应。仿真结果表明该方法的混响效果与镜像源法接近,明显优于反馈延迟网络法,但其计算复杂度比镜像源法低,便于实时应用。     

Hearing myself with others: Sound levels in choral performance measured with separation of one's own voice from the rest of the choir

The choir singer has two acoustic signals to attend to: the sound of his or her own voice (feedback), and the sound of the rest of the choir (reference). The balance in loudness between feedback and reference is governed mainly by the room acoustics. Although earlier experiments have shown that singers have a fairly large tolerance for imbalance, with references ranging from −23 to +5 dB, experience suggests that, when singers are given control over this parameter, their preferences are much narrower. A quantification of the optimum balance would be useful in the design of concert stages and rehearsal halls. A method is described for measuring the feedback and reference levels as experienced by singers under live performance conditions. Recordings were made using binaural microphones worn by choir singer subjects. With the given combination of choir and room, it was possible to achieve adequate separation of the feedback and reference signals with simple signal processing. The feedback-to-reference ratio averaged over the 12 singers was found to be +3.9 dB, with extremes of +1.5 and +7.3 dB.     

Feedback law design and the Liapunov approach

We study the problem of designing targeting-type feedback control laws for systems with state and control constraints. A systematic approach to this problem is described in terms of a number of Liapunov-like criteria. This approach is presented in tutorial form and is illustrated by means of two examples having some background in the literature.This work was supported by the National Science Foundation under Grant ECS-8210284.