基于PLC的有载分接开关控制器的研制

本文介绍了一种基于PLC的有载分接开关控制器 ,该控制器可以显著提高控制系统的可靠性 ,简化系统接线。同时 ,通过PLC的通信端口与上位工业控制计算机相连 。

新型智能有载分接开关控制器的设计

随着电网智能化程度越来越高,人们对电力的安全可靠性和电能质量的要求逐渐提高。有载分接开关作为电力变压器的重要配套设备,其安全可靠性至关重要。因此,设计了一种新型智能有载分接开关控制器,实现对有载分接开关的调压,同时可以通过采集轻瓦斯气体继电器放气信号,智能分析判断是否需要对有载开关进行放气和检修,从而进一步提高了变电站的自动化水平和电网供电的可靠性。

分时段负荷控制器在农网中的应用

在农网中,农业季节性用电负荷占据很大比重,在用电高峰期变压器重过载现象严重,传统的解决办法是由供电所工作人员到田间地头组织用户轮流用电,这一方式需要到现场拆、接线停送电,工作量大,风险高,存在安全隐患。采用分时段负荷控制器,可以避免农灌用电高峰期用电扎堆的现象,通过实施有序计划用电,解决变压器过载问题。并且能根据负荷变化和需求随时自动调整供电时间,大大减少了工作人员的现场工作量。此装置最大的特点在于当配变不超载时,能够最大限度地满足客户用电需求;当配变超载时,自动执行有序用电方案。

新型摊铺机输分料自动控制系统设计

根据摊铺机输分料控制系统的高精确性和连续供料的要求,提出了一种基于超声波测距的新型摊铺机输分料自动控制系统;该系统以Atmega128单片机作为主控制器,通过超声波测距测量物料厚度,并结合TCN75芯片实现温度检测以补偿测量误差;通过闭环PID算法控制PWM脉冲输出,进而控制输分料电磁阀的开度和分料速度;RS485通信接口实现基于Modbus协议的远程控制;实测数据表明,该系统达到了对物料厚度的精确控制,具有较大的实践价值。

基于相平面的分布式驱动电动汽车稳定性控制

为提高分布式驱动电动汽车的操纵稳定性,提出一种基于相平面法的行驶稳定性控制策略。首先,建立非线性车辆2自由度模型,获得不同路面附着系数下车辆质心侧偏角相平面稳定域边界模型。其次,基于质心侧偏角相平面设计分区域控制器,当车辆处于稳定域内时,采用模糊神经网络控制器来决策横摆力矩,使车辆跟随目标变量;当车辆处于稳定域外时,设计失稳度和模糊神经网络联合控制器决策总横摆力矩,使车辆恢复稳定。最后,基于Simulink和CarSim仿真平台在蛇行绕桩和双移线工况下对稳定性控制方法进行仿真,并进行实车测试验证,结果证明了本文中所提控制策略的可行性和有效性。

基于Atmega128的摊铺机输分料控制系统设计

针对摊铺机对输分料控制系统的高精确性和连续供料的要求,根据超声波测距原理,提出了一种基于Atmega128的超声波输分料控制系统。该系统通过PID调节实现超声波测距,结合TCN75芯片实现温度检测以补偿测量误差,通过PWM输出控制电磁阀开度,并通过基于MODBUS的RS485通信实现远程控制。最后,给出了输分料控制系统的实验测距数据,表明了该输分料控制系统可以达到对物料厚度的精确控制。

基于单片机智能照明控制系统设计

本系统设计了针对楼宇的智能照明控制系统,该照明控制系统的主控制器、分控制器分别采用AT89C51和AT89C2051单片机实现控制,实现了有线通信、无线数传、控制及显示等功能,通过现场总线RS485通信方式实现照明灯具的智能控制,使光源具备自动调节功能。本系统在节约能源、延长照明灯具寿命、改善工作环境、创造良好环境气氛、提高人民生活水平等方面起到了重要的作用。

水平井分段遥控分采技术研究与应用

为了降低或控制水平井含水上升,延长水平井生产寿命,研究了水平井分段遥控分采配套技术。该技术利用封隔器将水平井水平段封隔成若干段,在对应的每一个目的层段安装一套遥控分采控制器进行分层生产。在需要调层生产时不需要起下管柱,通过套管加液压来改变遥控分采控制器的开关状态,每个遥控分采控制器在地面加压时反馈各自独立不同的示位信号,使地面工作人员完全了解每次操作后是哪一个遥控分采控制器进行了换向,可避免多次加压后造成的开关状态混乱,从而实现分段找水、堵水和采油于一体的新技术。现场应用表明,分采控制器3次换向均取得了成功,控水增油效果明显。

教室节能智能照明控制系统设计

文章从节能和方便控制出发,以高校教学楼照明为研究方向,阐述了智能照明控制系统设计过程。该照明控制系统利用单片机作为主、分控制器,通过软件与硬件相结合的设计方式,实现了主、从控制器之间的有线通信、键盘功能输入、控制与显示等功能。

无线可视对讲门禁系统中图像通信的设计与实现

设计一种以单片机AT89C51为核心,以SRWF-1,CAMERA OV 7620,IDT7205等为外围芯片的无线可视对讲电路,整个电路围绕图像的采集、传输、显示进行探讨。阐述了无线可视对讲电路中的软硬件处理技术。仿真结果表明,该可视对讲电路具有单色位图采集、按键确认访问房间号、无线传输图像信号、LCD显示单色位图、振铃呼叫等功能。与已有系统相比,该系统把低速单片机应用于数据量大的图像信号采集和图像短距离无线传输上,取得了较好的效果。

ADRC FRACTIONAL ORDER PID CONTROLLER DESIGN OF HYPERSONIC FLIGHT VEHICLE

Active disturbance rejection controller（ADRC）uses tracking-differentiator（TD）to solve the contradiction between the overshoot and the rapid nature.Fractional order proportion integral derivative（PID）controller improves the control quality and expands the stable region of the system parameters.ADRC fractional order（ADRFO）PID controller is designed by combining ADRC with the fractional order PID and applied to reentry attitude control of hypersonic vehicle.Simulation results show that ADRFO PID controller has better control effect and greater stable region for the strong nonlinear model of hypersonic flight vehicle under the influence of external disturbance,and has stronger robustness against the perturbation in system parameters.

应变液晶研究进展

近年来在聚合物分散液晶与聚合物网络液晶研究中发现的应变液晶(stressed liquid crystal,SLC)引起国外研究者的极大兴趣。鉴于国内还缺乏相关研究的报导,本文综述了应变液晶之剪切液晶、拉伸液晶及压缩液晶的概念、基本理论和独特电光特性;并分别介绍了其在快速转换装置、大相位调制材料、空间光调制器、大孔径液晶透镜及棱镜、以及可调光栅等方面应用的研究进展以及可能在微显示、光学衍射元件和分光器件上的应用。

PCA-CMAC based machine performance degradation assessment

A principal component analysis-cerebellar model articulation controller （PCA-CMAC） model is proposed for machine performance degradation assessment.PCA is used to feature selection,which eliminates the redundant information among the features from the sensor signals and reduces the dimension of the input to CMAC.CMAC is used to assess degradation states quantitatively based on its local generalization ability.The implementation of the model is presented and the model is applied in a drilling machine to assess the states of the cutting tool. The results show that the model can assess the wear states quantitatively based on the normal state of the cutting tool.The influence of the quantization parameter g and the generalization parameter r in the CMAC model on the assessment results is analyzed.If g is larger,the generalization ability is better,but the difference of degradation states is not obvious.If r is smaller,the different states are distinct,but memory requirements for storing the weights are larger.The principle for selecting two parameters is that the memory storing the weights should be small while the degradation states should be easily distinguished.

Simulation Research on Structure Changing Control over the Follow Up System of the Smart Mine

By analyzing the target's motion pattern, in terms of the requirement for the performance indexes of the follow up system, the structure changing control and time optimal theory is proposed. The system's control scheme from three different aspects(the dynamic response simulation, compound control simulation and dynamic tracking simulation) is also studied. And all the results proved the feasibility of the synthetical utilization of the open loop control, speed decreased control and position closed loop control.

A 2GHz Low Power Differentially Tuned CMOS Monolithic LC-VCO

A 2GHz differentially tuned CMOS monolithic LC-VCO is designed and fabricated in a 0.18μm CMOS process. The VCO has a 16.15% tuning range （from 1. 8998 to 2. 2335GHz） through a combination of analog and digital tuning techniques （4-bit binary switch-capacitor array）. The measured phase noise is - 118.17dBc/Hz at a 1MHz offset from a 2. 158GHz carrier. With the presented improved switch,the phase noise varies no more than 3dB at different digital control bits. The phase noise changes only by about 2dB in the tuning range because of the pn-junctions as the varactors. The VCO draws a current of about 2. lmA from a 1.8V power supply and works normally with a 1.5V power supply.

ANALYSIS AND SIMULATION OF CONTROL MIXER CONCEPT FOR A CONTROL RECONFIGURABLE AIRCRAFT

In today's aircraft,the hardware redundancy is driven by the critical surfaces resulting in single point-failures.Reconfiguration technology remoVes the single surface criticality by employing control surfaces with aerodynamic redundancy.This paper studies a control reconfiguration scheme based on Control Mixer Concept.A technique for the design of a control mixer for an aircraft with damaged surfaces/actuators using the pseudo-inverse is developed and applied.This paper discusses its applications and limitations based on linear analysis and computer simulation.

Active Vibration Control and Stability Analysis of Cantilever Plate

Active vibration control and stability analysis of cantilever plate are discussed. Based on the analysis of characteristic equation of the closed loop control system, it is shown that such an active control may increase damping properties of the system, meanwhile it may result in instability of the system. It is stable when the feedback only occurs between the collocated sensors and actuators, but it may be unstable when there exists the feedback between sensors and actuators, which mainly depends on the property of the gain matrix of feedback. If the gain matrix is symmetric and definitely positive, the system is stable.

ANALYSIS FOR THE BEZOUT IDENTITY OF GENERALIZED SYSTEMS

The state space representation of the Bezout identity for generalized systems proposed by (Wang and Balas, 1989) is discussed again. A more concise way of description and proof is presented and the physical significance of the result in is also analyzed. Thus, our work is of independent interest.

Observer-based Iterative and Repetitive Learning Control for a Class of Nonlinear Systems

In this paper, both output-feedback iterative learning control(ILC) and repetitive learning control(RLC) schemes are proposed for trajectory tracking of nonlinear systems with state-dependent time-varying uncertainties. An iterative learning controller, together with a state observer and a fully-saturated learning mechanism, through Lyapunov-like synthesis, is designed to deal with time-varying parametric uncertainties. The estimations for outputs, instead of system outputs themselves, are applied to form the error equation, which helps to establish convergence of the system outputs to the desired ones. This method is then extended to repetitive learning controller design. The boundedness of all the signals in the closed-loop is guaranteed and asymptotic convergence of both the state estimation error and the tracking error is established in both cases of ILC and RLC. Numerical results are presented to verify the effectiveness of the proposed methods.

Inhibition characteristics of circulating current in parallel inverter driving system of mine hoist

This research investigated the outputting circulation current inhibition characteristic which are controlled by the instantaneous feedback voltage in inverter parallel driving of the mine hoist. We established a transfer function of the parallel inverters controlled by the close-loop adjustment of instantaneous voltage feedback. The influence of the parameters of the close-loop feedback circuit to the inhibition effects to the outputting circulation current is observed. After analyzing the circulating current inhibition characteristics, the proportion integration （PI） controller is introduced into the close-loop adjustment by instantaneous voltage feedback. The characteristics equation is gained to determine the PI parameters by drawing the Bode plots. The inhibition effects of the proposed controller are examined by the established simulation model of parallel inverter system. The harmonic distortion rate at the outputting voltage frequency value of 4, 10, 20, 41 and 50 Hz, are all lower than 2.32 % by the instantaneous outputting voltage feedback.