时分复用光纤光栅传感阵列中DFB激光器的高精度温控设计

针对时分复用光纤光栅(TDM-FBG)传感阵列中使用的分布反馈(DFB)激光器高波长稳定度的要求,设计了一个高精度的DFB温控方案,包括温度测量与设定、热敏电阻线性化、PID补偿回路、H桥驱动、温度电压采集与显示等。使用DFB内置的热敏电阻和半导体制冷器(TEC)对温控电路进行了测试,其精度在180s内达到±0.04℃,温控后激光器温度变化引起的应变测量误差为±3.4με左右,满足TDM-FBG传感阵列的要求。     

多用户MIMO系统低复杂度收发联合波束成形方案

基于多用户多输入多输出(MIMO)有限反馈系统提出了一种收发联合波束成形方法。该方法在发送端采用每个用户酉速率控制(PU2RC)波束成形技术,在接收端采用基于信干噪比(SINR)最大化的天线合并算法。天线合并算法利用用户SINR的广义Rayleigh熵特性寻找最佳的天线合并矢量。仿真结果表明,该方法能充分利用信道信息,不仅改善了传统PU2RC系统的和速率性能,相对于已有的迫零(ZF)联合波束成形方法,对信道状态信息的量化误差的敏感性更低,用户选择算法的复杂度更低,且低速率反馈条件下和速率性能更优。     

基于组反馈融合机制的视频超分辨率模型

视频超分辨率（video super-resolution,VSR）的目的是利用多个相邻帧的信息来生成参考帧的高分辨率版本。现有的许多VSR工作都集中在如何有效地对齐相邻帧以更好地融合相邻帧信息,而很少在相邻帧信息融合这一重要步骤上进行研究。针对该问题,提出了基于组反馈融合机制的视频超分辩模型（GFFMVSR）。具体来说,在相邻帧对齐后,将对齐视频序列输入第一重时间注意力模块;然后,将序列分成几个小组,各小组依次通过组内融合模块实现初步融合。不同小组的融合结果经过第二重时间注意力模块;然后,各小组逐组输入反馈融合模块,利用反馈机制反馈融合不同组别的信息,最后将融合结果输出重建。经验证,该模型具有较强的信息融合能力,在客观评价指标和主观视觉效果上都优于现有的模型。     

Robust pole assignment for incomplete nonlinear decoupling applied to robots

A robustness analysis and synthesis for incomplete nonlinear decoupling for a class of nonlinear systems is discussed. Rigid and elastic-joint robot models belong to this class. For the elastic case, a transformation facilitates the robustness analysis under a weak assumption. Charts with H ₁- and H - norms of closed-loop disturbance transfer functions of the nonlinear-decoupled system are presented for a robust pole assignment.     

众筹项目推荐:面向隐式反馈的深度学习协同过滤

目前,在推荐系统研究中,用户的隐式反馈,以及极度稀疏的数据,已成为影响协同过滤推荐效果的主要问题.针对这一现象,本文提出了深度学习协同过滤算法,先利用卷积神经网络,对用户-项目矩阵的隐层特征进行学习,再结合协同过滤,对用户-项目的交互信息进行建模,并将两种特征融合预测推荐列表.以众筹平台的数据为实验对象,比较模型中各参数对推荐效果的影响,并设计与基线方法的对比实验.实验结果表明:均匀采集负反馈,并在一定卷积层数的网络中,数据稀疏度越高,效果越好;对比基线方法,本文提出的算法在公开数据集(Yahoo!Movie)上取得了最好的推荐结果.本文提出的算法有助于提高众筹平台的融资成功率,同时也丰富了推荐系统的研究体系.     

压风机恒压供风系统设计

针对某矿压风机往井下输送高压空气时存在输气总管压力波动大且调节困难的问题,设计了一种基于变频调速和闭环负反馈控制的压风机恒压供风系统。该系统通过输气总管上的压力传感器采集实时压力信号,与输入压力信号比较后得到偏差信号,PLC对偏差信号进行分析和处理,并输出相应的变频器调节信号,使变频器改变压风机电动机的电源频率,从而达到调节输气总管压力的目的。实际应用表明,该系统运行稳定、可靠,实现了输气总管高压空气的恒压输送。     

一类非自衡对象的典型反馈型PID控制

针对一类非自衡对象,提出了一种基于典型反馈模型的PID控制器(TF-PID);采用全极点型逼近方法对被控对象的时滞环节做近似处理,并在内模控制原理的基础之上导出一种基于典型反馈模型的PID控制器参数整定策略,从而得到PID控制器的整定参数;仿真结果表明,所设计的控制方法具有更优的设定值跟踪性能和干扰抑制性能,并且实现二者分离控制。     

具有时变状态滞后2-D离散系统的稳定与镇定(英文)

针对一类由局部状态空间(LSS)Fornasini-Marchesini(FM)第二模型描述的,具有时变状态滞后的2-D离散系统,其中时变滞后项的上、下界均为正实数,研究了其稳定性和控制综合问题。首先,利用Lyapunov-Krasovski泛函方法,提出了系统的稳定性准则。再根据这一准则,分别设计状态反馈和动态输出反馈控制器保证系统的稳定性。状态反馈控制律和输出反馈矩阵可由线性矩阵不等式(LMI)求得。最后,通过数值算例说明所得结果的有效性。     

Gain‐scheduled dynamic output feedback control for discrete‐time LPV systems

This paper presents synthesis conditions for the design of gain‐scheduled dynamic output feedback controllers for discrete‐time linear parameter‐varying systems. The state‐space matrix representation of the plant and of the controller can have a homogeneous polynomial dependency of arbitrary degree on the scheduling parameter. As an immediate extension, conditions for the synthesis of a multiobjective ??_∞ and ??₂ gain‐scheduled dynamic feedback controller are also provided. The scheduling parameters vary inside a polytope and are assumed to be a priori unknown, but measured in real‐time. If bounds on the rate of parameter variation are known, they can be taken into account, providing less conservative results. The geometric properties of the uncertainty domain are exploited to derive finite sets of linear matrix inequalities based on the existence of a homogeneous polynomially parameter‐dependent Lyapunov function. An application of the control design to a realistic engineering problem illustrates the benefits of the proposed approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Delay‐dependent passivity and passification for uncertain Markovian jump systems with time‐varying delays

This paper deals with the problems of passivity analysis and passivity‐based controller design for Markovian jump systems with both time‐varying delays and norm‐bounded parametric uncertainties. Firstly, new delay‐dependent conditions for the considered system to be passive are obtained by using a mode‐dependent Lyapunov functional and by introducing some slack variables. These conditions are expressed by means of LMIs that are easy to check. It is shown through a numerical example that the obtained passivity conditions are less conservative than the existing ones in the literature. Secondly, the passification problem is investigated. On the basis of the obtained passivity conditions, dynamic output‐feedback controllers are designed, which ensure that the resulting closed‐loop system is passive. The effectiveness of the proposed design method is demonstrated by a numerical example. Copyright © 2011 John Wiley & Sons, Ltd.