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焦炭气孔率是焦炭的重要技术指标,其测定方法已形成国家标准.设计了基于S7-200PLC和MCGS触摸屏的焦炭气孔率真空法测定监控系统,介绍了系统的硬件配置、控制策略和设计特点.该系统可靠性高,操作简单,监控方式多样. 相似文献
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CM(连续媒介continuous media)实时性要求高,信道的资源是有限的,针对这个问题本文提出了用基于遗传算法的神经网络控制策略来控制CM包的平均延时,从而更有效地利用信道资源,提高QOS服务效能. 相似文献
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在分析逻辑门限值防抱死制动控制策略和自寻优制动防抱死控制策略的基础上,综合以上2种方法的优点,采用了自寻优和门限值相结合的综合控制策略.能够根据面的变化.自动寻找到最佳滑移丰点使ABS在其附近工作.充分利用了路面特性,提高ABS的制动效能.用AMESim和Mat-lab/Smiulink联合建立单轮车辆制动模型,并建立了液压系统模型,提高模型的精度,取得了较好的仿真结果.验证了该控制策略的有效性. 相似文献
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王艳红 《北京工业职业技术学院学报》2007,6(4):7-10,16
透平和压缩机组的自动控制系统的控制算法复杂,对控制系统的安全性要求非常高。因此,在控制系统中一般采用双重冗余或三重冗余控制器。介绍了ICS Triplex的防喘振控制算法和控制策略,初始喘振检测、容量控制和透平速度控制。这种控制算法和控制策略将决定防喘振控制线的精确度,完善控制策略,避免压缩机喘振。同时,使压缩机运行区域增大,可减少压缩机防喘振阀的打开次数,节约能源。 相似文献
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《蒙自师范高等专科学校学报》2015,(5):38-39
文章阐述了变频恒压供水系统的PID控制策略分析,分别介绍了PID算法常用的三种控制策略,即硬件型PID控制器控制、PLC内置软件型PID控制、变频器内置型PID控制,最后对以上三种控制策略进行归纳总结. 相似文献
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介绍了矩阵变换器的基本工作原理,永磁同步电机的数学模型,驱动系统采用直接转矩控制策略.给出了实验样机的主电路、控制电路以及软件设计方案.仿真结果表明矩阵变换器驱动的同步电机,具有良好的输入输出性能,电网侧功率因数高,具有优越的静态和动态性能. 相似文献
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混合动力汽车的优化目标是在满足动力性及其各部件性能约束的前提下减少油耗并降低排放.这些特性除了与动力系统各部件参数有关,同时还受控制策略参数影响.本文以并联式混合动力车为研究对象,应用的多目标遗传算法,采用非占优排序方法来处理多个目标函数,将油耗和排放同时作为优化目标,优化控制策略参数,从而得到这类集成优化问题的Pareto最优解集,可以为控制策略参数的设定提供多种选择. 相似文献
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利用Simulink搭建带电极调节器的交流电孤炉系统的仿真模型.改变电极调节器的控制策略,分别采用PID和模型参考自适应的控制方法,得到电网电压波动的仿真结果.仿真结果表明采用先进的控制策略,提高了电极调节系统的性能,使得电弧炉引起的电网电压波动的幅值大大减小. 相似文献
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马佳骝 《洛阳工业高等专科学校学报》2012,22(3)
双馈感应发电机特殊的电路结构使其在并网运行时对电网电压跌落非常敏感,通过Crowbar保护电路短接转子是目前常采用的实现双馈感应发电机低电压穿越的措施,其主要缺点是此时双馈机运行于异步机状态,需要从系统吸收无功进行励磁.本文对双馈感应发电机电压跌落下的运行特性进行了分析,在总结了传统的Crowbar投切控制策略优缺点的基础上提出了一种改进的Crowbar投切控制策略.在MATLAB/Simulink仿真平台下搭建并网双馈机风电场模型,对双馈机低电压穿越运行特性和所提的Crowbar投切控制策略进行仿真分析.仿真结果证明了所提的改进的Crowbar投切控制策略的有效性. 相似文献
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针对当代大型天文望远镜驱动伺服系统中存在的非线性干扰,分析了非线性干扰的类型。在此基础上建立了大型望远镜驱动控制系统的数学模型,提出了高阶滑模控制方案,将系统中存在的不连续性拓展到状态控制的最高阶,抑制系统的高频振动现象,克服了普通滑模控制的缺点数值仿真证明了该方案的可行性和有效性。 相似文献
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Rong-hua HUAN Wei-qiu ZHU Yong-jun WU 《浙江大学学报(A卷英文版)》2008,9(3):351-357
A modified nonlinear stochastic optimal bounded control strategy for random excited hysteretic systems with actuator saturation is proposed. First, a controlled hysteretic system is converted into an equivalent nonlinear nonhysteretic stochastic system. Then, the partially averaged Itoe stochastic differential equation and dynamical programming equation are established, respectively, by using the stochastic averaging method for quasi non-integrable Hamiltonian systems and stochastic dynamical programming principle, from which the optimal control law consisting of optimal unbounded control and bang-bang control is derived. Finally, the response of optimally controlled system is predicted by solving the Fokker-Planck-Kolmogorov （FPK） equation associated with the fully averaged Itoe equation. Numerical results show that the proposed control strategy has high control effectiveness and efficiency. 相似文献
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高等职业院校全面提高教学质量是实施科教兴国战略的必然要求,也是高职教育自身发展的客观要求。明确了教学质量、教学质量监控、监控主体和客体、监控依据等基本概念,阐释了信息采集与处理、评价与诊断、反馈与调控、惩罚与激励等教学质量监控过程的主要环节。 相似文献
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In order to deal with torque pulsation problem caused by traditional control method for brushless DC （BLDC） motor and to achieve high precision and good stability, a novel control strategy is proposed. Compared with the traditional control scheme, by using phase voltage as a control objective and making waveform of phase current approximately quasi-sinusoidal, torque ripple of BLDC motor is reduced from the original 14% to 3.4%, while toque is increased by 3.8%. Furthermore, by detecting zero-crossings of back electromotive force （BEMF） with non-conducting phases, sensorless control is realized. The new control strategy is simple. It can minimize torque ripple, increase torque, and realize sensorless control for BLDC motor. Simulation and experiments show good performance of BLDC motor by using the new control method. 相似文献
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Robert A. Bell Matthew F. Abrahams Catherine L. Clark Christina Schlatter 《Communication quarterly》2013,61(1):107-124
This study examined the reciprocal concessions and self‐presentation accounts of the door‐in‐the‐face (DITF) compliance strategy within a fundraising context. Subjects were classified as low or high in exchange orientation, and as low or high in approval motivation on the basis of a pretest questionnaire. As predicted on the basis of reciprocal concessions theory, a significant interaction was obtained between exchange‐orientation and message strategy. For high exchange‐oriented subjects, the DITF message strategy substantially increased compliance rates, relative to the single‐request control message. However, low exchange‐oriented subjects were actually more charitable in response to the control message. Analysis of a post‐treatment measure of obligation to the requestor revealed that obligation could account for less than half of the interaction effect, a finding which is inconsistent with concessions theory. Self‐presentation theory suggests that DITF should work best when directed toward targets who are high in their approval motivation, but this hypothesized interaction between approval motivation and message strategy did not materialize. 相似文献
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针对药品生产车间温度控制系统大滞后、大惯性、非线性等特点,提出了采用参数模糊自整定PID和Smith补偿等相结合的控制方法,通过仿真分析表明控制效果良好.文章重点讨论了系统控制策略的制定和模糊控制器的设计等内容. 相似文献
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陈德富 《武汉职业技术学院学报》2006,5(3):14-16
新兴技术具有高度的不确定性与创造性毁灭的特征。在高度不确定的环境下为新兴技术制定投资战略,是新兴技术成功的关键环节。在新兴技术研究开发(R＆D)、中试、商业化和生产经营规模化四个阶段要分别控制不同风险,保证投资的高收益。 相似文献
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Dynamic model and control strategy of parallel mechanism have always been a problem in robotics research. In this paper, different dynamics formulation methods are discussed first. A model of redundant driven parallel mechanism with a planar parallel manipulator is then constructed as an example. A nonlinear adaptive control method is introduced. Matrix pseudo-inversion is used to get a desired actuator torque from a desired end-effector coordinate while the feedback torque is directly calculated in the actuator space. This treatment avoids forward kinematics computation that is very difficult in a parallel mechanism. Experiments with PID together with the descibed adaptive control strategy were carried out for a planar parallel mechanism. The results show that the proposed adaptive controller outperforms conventional PID methods in tracking desired input at a high speed. 相似文献
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A novel topology of the current-source grid-connected inverter is proposed based on the immittance converter theory. A control strategy of sine-sine pulse width modulation （PWM） is studied. Compared with the traditional current-source inverter, the power frequency inductors and power frequency transformer are replaced with high frequency inductors and a high frequency transformer. Thus, the proposed inverter has advantages of small volume, low cost, low total harmonic distortion （THD）, low power losses, high power factor （PF） and simple control. Furthermore, grid voltage cannot influence output current of the grid-connected inverter and the current-source inverter with a high PF that approaches one has been realized. Finally, validity of the theory analysis and feasibility of the control scheme are shown by simulation and experimental results. 相似文献