PWM整流器保持高功率因数运行的方法研究

针对煤矿井下电压波动严重时影响稳压电源的单位功率因数等问题,提出采用可变输出直流电压法来控制PWM整流器的直流侧电压,以保证PWM整流器处于高功率因数运行的工作状态;详细分析了直流侧电压的选取及交流侧输入电压大范围波动对交流侧输入电流及功率因数的影响,介绍了可变输出直流电压法的控制原则及软件实现。试验结果表明,在电压波动情况下,可变输出直流电压法不仅可使PWM整流器系统稳定,而且可以保持整流器的高功率因数运行状态。     

数字音频水印的有效性和可靠性研究

针对音频水印的LSB算法的可靠性较差的问题,运用纠错编码和随机序列来提高水印系统的可靠性,通过增多水印的嵌入位数来提高水印系统的有效性。实验结果表明,水印系统的可靠性和有效性都得到了明显的改善。     

机器人一体机远程监控平台的音视频传输研究与设计

文章分析了一个典型的机器人一体机（RIM）远程控制方案,研究了该方案中的用于解决海量数据传输问题的监控平台。在数据传输过程中,音视频数据的传输效率是个亟待解决的问题。文章也对该控制方案中的结构进行了深入研究与分析,详细叙述了广域网音视频传输系统的需求,设计并实现了广域网中不同局域网之间的音视频信息的传输,为移动机器人的遥操作提供支持,介绍了系统所用到的关键技术并对系统进行了测试与分析。该方案简单明了,实现方便,通过了相关测试。     

基于PSO的负反馈电路参数自适应优化及仿真分析

采用粒子群优化算法,以电压增益、共模抑制比、输入电阻平方根的三者乘积对输出电阻的比作为适应度函数,对差分 共射两级直接耦合电压串联负反馈放大电路中的电阻做自适应优化。结果显示,只要对电路交流指标加以约束,适应度函数值总会减小。当分别对增大电压增益和减小输出电阻进行限制后,电压增益总是尽量小,输出电阻总是尽量大,以使适应度函数在给定约束下取得最大。经EWB软件对优化参数仿真,结果满足线性放大要求。同时说明了可以调整适应度函数形式,找到最佳电路参数,以满足工程上对放大器指标的不同需求。     

一种基于RFID的炼钢投入产出分析系统

为了控制物料消耗、降低吨钢成本,设计一种基于RFID的炼钢投入产出分析系统.     

Hierarchical inversion‐based output tracking control for uncertain autonomous underwater vehicles using extended Kalman filter

In this study, a hierarchical inversion‐based output tracking controller (HIOTC) is developed for an autonomous underwater vehicle (AUV) subject to random uncertainties (e.g., current disturbances, unmodeled dynamics, and parameter variations) and noises (e.g., process and measurement noises). The proposed HIOTC respectively utilizes a combination of feedforward and feedback controls in a hierarchical structure based on the kinematic and dynamic models of the system. Moreover, to obtain uncontaminated or unavailable states for implementing the proposed control law, the extended Kalman filter (EKF) is employed to estimate the system states. Then, the position outputs, orientation, and velocity of the AUV are reached with guaranteed asymptotic stability. The robustness of the proposed HIOTC is verified through injection of random uncertainties into the system model. The closed‐loop stability of the proposed individual subsystems is respectively guaranteed to have uniformly ultimately bounded (UUB) performance based on the Lyapunov stability criteria. In addition, the asymptotic tracking of the overall system is demonstrated using Barbalat's lemma. Finally, the feasibility and effectiveness of the proposed control scheme are evaluated through computer simulations and it is shown that the overall system achieves good asymptotic tracking performance.     

Global robust output tracking control for a class of cascade nonlinear systems with unknown control directions

We investigate the global robust tracking problem via output feedback for a class of cascade nonlinear systems with dynamic uncertainties and non-vanishing disturbances. It does not require a priori knowledge of the sign of the high-frequency gain. A recursive design scheme is presented using the ideas of pseudosign function, Nussbaum-type gain technique and the deadzone method. It is shown that under some conditions, the tracking error can be guaranteed asymptotic to the interval [?ε, ε]?? with arbitrary prescribed ε>0 after a finite time, while keeping all signals of the resulting closed-loop systems bounded. The simulation results demonstrate the effectiveness of the proposed algorithm.     

基于T-S 模糊模型的采样数据网络控制系统H∞ 输出跟踪控制

研究具有采样数据的基于T-S (Takagi-Sugeno) 模糊模型网络控制系统H输出跟踪控制问题. 提出将采集器端数据采样周期、数据传输时滞和数据丢包转换为零阶保持器端数据更新周期, 在此基础上, 利用输入时滞法和PDC (Parallel distributed compensation) 技术, 建立网络环境下被控对象和参考模型合并的基于T-S 模糊模型的增广系统模型. 通过Lyapunov 方法, 并充分利用采样特性, 给出系统实现H输出跟踪的充分条件, 以及可靠模糊控制器的设计. 仿真结果表明所设计模糊控制器能够实现该类系统良好的跟踪.     

压力传感器在线状态监测装置研发

目前煤炭输送皮带采用双托辊(2个传感器)或四托辊(4个传感器)并采取传感器输出信号并联方法,以此提高皮带秤的准确性和稳定性.然而该并联方法无法对传感器进行独立采集,同时影响了传感器的故障判断.采用MSC1210Y5单片机和信号分离器,设计并联称重传感器系统的压力传感器状态在线监测装置,实现多个压力传感器并联应用时的独立采集;设计压力传感器在线状态比对算法,将不断变化的称重累计量转换为定量值,解决称重累计量为变量而无法准确在线监测的技术弊端.测试结果表明该装置较好地满足了压力传感器独立采集的要求,为称重计量装置等集中监控提供有效手段.     

Performance control for interconnection of identical systems: Application to PLL network design

In this paper, the problem of the control law design for interconnected identical systems ensuring the global stability and the global performance properties is under consideration. Inspired by the decentralized control law design methodology using the dissipativity input–output approach, the problem is reduced to the problem of satisfying two conditions: (i) the condition on the interconnection and (ii) the condition on the local subsystem dynamics. Both problems are efficiently solved applying a (quasi‐) convex LMI optimization and standard H_∞ synthesis. The proposed design methodology is applied to the control law design of a synchronous PLL network. Copyright © 2014 John Wiley & Sons, Ltd.