Beam-Loading Compensation for RF Gun by Feed-Forward Control System

A feed-forward automatic control system based on a novel control principle is developed, in order to compensate the amplitude and phase fluctuations of the microwave field in the thermionic RF gun cavity. The fluctuations, which are mainly caused by beam-loading effect, can be effectively restrained through this method. It is experimentally demonstrated that the novel control system has the excellent characteristics of stability and reliability.     

Efficiency-Optimized Speed Control System Synthesis Method Based on Improved Optimal Regulator Theory?Application to Separately Excited DC Motor System

A new synthesis method for the efficiency-optimized speed control system for the separately excited dc motor system is proposed on the basis of an improved optimal regulator theory. The optimal ratio of the armature current and the field current that gives the maximum efficiency is analytically derived, and the error term of the current ratio is included in a performance index. Then, the control system which realizes both the satisfactory response and the optimal current ratio giving the optimal efficiency is constructed in the systematic design procedure. In simulational and experimental results, close agreement between them is obtained. Also, considerable improvement on the efficiency of the motor system at the steady state is obtained.     

一种新的自适应偏振模色散补偿前馈方法

提出了一种新偏振模色散（PMD）补偿的方法，直接从被补偿光纤中提取偏振色散矢量的大小和方向信息，根据算法调节偏振模色散补偿器的各参量，使得补偿器的快轴与被补偿光纤的慢轴对准，从而使得偏振模色散得到补偿。这种方法的优点是减少了搜索的自由度。建立了40Gb／s偏振模色散前馈补偿系统，并通过数值模拟．对40Gb／s的非归零（NRZ）码的偏振模色散进行了自适应补偿。通过对补偿前后的眼图、偏振度（DOP）和Q值进行对比和分析，结果表明，这种偏振模色散补偿的前馈方法是非常有效的。     

主动转速补偿策略的卷取机交流传动直接转矩控制系统

通过对热连轧卷取机系统的电机转速规程进行分析,针对实际生产中由加速度和轧机振动因素导致的卷取张力波动问题,提出一种新型张力控制模型.并且结合负荷观测与主动转速补偿的思想,在未安装转矩和轧辊转速传感器的条件下,首次对于这类有既定速度规程的交流电力拖动系统,设计出一种具有强抗扰能力的直接转矩控制系统.实验结果显示采用主动负荷观测与转速补偿控制方法,能够克服普通直接转矩控制系统的固有缺陷,减小电机转速波动与输出转矩的耦合,实现恒张力卷取的控制目标.     

高速浮辊张力控制系统的研究

针对高速浮辊张力控制机构的数学模型进行了分析,并采用张力传感器、力矩伺服电机及运动控制平台构成张力闭环控制实验装置,实现了在高速走线过程中对张力的控制,并对影响张力控制的因素进行了分析。     

三相PWM整流器的前馈解耦控制与仿真研究

基于前馈解耦控制策略,研究了三相电压型PWM整流器的建模与控制问题。首先,在d-q旋转坐标系下建立了三相电压型PWM整流器的数学模型,给出了三相电压型PWM整流器的双闭环控制结构,按此方法确定了电压、电流PI调节器的设计方法。仿真结果表明该方法能使所设计的PWM整流器运行于单位功率因数,输出的直流电压稳定在期望值且具有快速的动态响应,满足了设计要求。     

Microprocessor-Based Speed Control System for High-Accuracy Drives

A digital speed control system for a dc motor with a pulse tachogenerator for speed sensing is described. A microprocessor is used for fast speed measurement with a response time constant of the order of 8 ms and a resolution of 0.0125 percent of the top speed. This has become possible because of the principle of obtaining the latest speed value based on the previous speed value. This paper describes the principle of speed measurement and control, the flowchart, and the experimental results. A closed-loop speed holding accuracy of ±0.025 percent of the top speed is obtained.     

自适应低速摩擦补偿

低速抖动问题,是伺服系统特性研究过程中的重要分支之一.转台伺服系统的低速工作精度主要受到摩擦力矩、电机波动力矩、测量元件和反馈元件死区特性等诸多因素的影响.而低速精度的提高,主要受到以摩擦力矩为主的系统扰动力矩的限制,因此在对系统干扰力矩对转台伺服系统低速特性影响的研究中,一个重要的方面就是如何对摩擦力矩进行补偿的研究.本文首先对摩擦模型进行了讨论,然后给出了详细的自适应控制的补偿结果.     

A Linear-State Feedback Plus Adaptive Feed-Forward Control for DC Servomotors

This paper proposes a linear-state feedback plus adaptive feed-forward control to control position for DC servomotors. The aim is to control DC servomotors submitted to inertia and Coulomb friction variations. Conditions for stability depending on the frequency richness of the reference input are presented. Experimental results show the improvement with respect to classical tachometric feedback.     

直流调速系统转速闭环控制的建模与仿真

阐述了转速闭环控制的直流调速系统的工作原理,并且详细研究了在MATLAB/Simulink中的转速闭环控制的直流调速系统的建模方法,最后给出了反映系统性能的仿真结果并对其进行了比较分析,为转速闭环控制的直流调速系统在实际工程中的应用有很好的借鉴意义。     

A Robust High Speed Serial PHY Architecture With Feed-Forward Correction Clock and Data Recovery

This paper describes a robust architecture for high speed serial links for embedded SoC applications, implemented to satisfy the 1.5 Gb/s and 3 Gb/s Serial-ATA PHY standards. To meet the primary design requirements of a sub-system that is very tolerant of device variability and is easy to port to smaller nanometre CMOS technologies, a minimum of precision analog functions are used. All digital functions are implemented in rail-to-rail CMOS with maximum use of synthesized library cells. A single fixed frequency low-jitter PLL serves the transmit and receive paths in both modes so that tracking and lock time issues are eliminated. A new oversampling CDR with a simple feed-forward error correction scheme is proposed which relaxes the requirements for the analog front-end as well as for the received signal quality. Measurements show that the error corrector can almost double the tolerance to incoming jitter and to DC offsets in the analog front-end. The design occupies less than 0.4 ${hbox {mm}} ^{2}$ in 90 nm CMOS and consumes 75 mW.      

基于DSP直流电机速度的模糊控制系统研究

介绍一种基于模糊控制的直流电机速度控制系统。该模糊控制器设计为二维模糊控制器,以速度反馈和给定转速的误差及误差的变化率作为模糊控制器的输入变量,采用带调整因子的模糊控制器不需要建立模糊查询表。运用DSP强大的计算能力直接按实时计算输出控制量,实现编码器的解码、速度的测量。试验表明系统具有较强的鲁棒性和抗干扰能力,适应于各种不同的场合。     

舰载雷达中的舰速补偿

舰载雷达的MTI、MTD系统必须补偿由于载体运动而产生的多普勒频率的影响。本文分析了用数字方法进行舰速补偿,并作了实验,结果表明:这种补偿对舰速、舷角、仰角、雷达工作频率、重复频率代码等的量化精度都提出了严格要求。     

舰载雷达的舰速补偿

舰艇在运动的时候,会对雷达目标回波附加一个多普勒速度。如果不把这个多普勒速度补偿掉,那么信号经过动目标检测（MTD）处理后的结果将会是不准确的,这种信号是无法使用的。详细阐述了舰速补偿的原理,并介绍了舰速补偿的具体实现方法。     

无刷直流电机变频调速控制系统仿真研究

针对如何才能获得无刷直流电机的优良调速性能这一问题,设计了一种闭环控制系统,速度反馈控制使电机的运行性能更加稳定,控制器单元向逆变器提供脉宽调制信号、开关管的开关次序,从而实现了变频调速控制。此系统在Matlab/Simulink平台上进行了模型搭建及仿真,数值仿真结果表明,文中控制系统具有良好的可行性及有效性。     

基于负载电流前馈的风电系统网侧变流器控制

对于具有并网变流器的风电系统,本文提出了一种基于负载电流前馈的网侧变流器矢量控制方法。与传统方法相比,该方法可提高风电系统在最大风能捕获过程中的暂态稳定性和抑制电网电压波动对直流母线电压所造成的影响。本文以双馈发电机型风电系统为例进行了理论分析和仿真实验,结果验证了所提方法的正确性和有效性。     

智能车速度控制系统设计与实现

本文针对智能车的速度控制系统进行了深入研究,在此基础上提出了新颖的速度"多模式"控制算法。实践证明,该算法对于这个近似一阶惯性环节的系统控制效果良好。     

高精度高速振镜控制系统设计

针对目前扫描成像中的振镜控制系统功耗高、体积大、控制精度低和控制复杂等缺点,设计出一种高速、高精度振镜控制系统。分析了系统的工作原理,叙述了系统的硬件设计和软件算法设计,详细介绍了振镜控制系统的数字控制电路设计和驱动电路设计,并研制出了振镜控制系统。实验结果验证了振镜控制系统的可行性,系统运行稳定可靠,成功应用于动态稳像系统,有较大的应用前景。