共查询到18条相似文献,搜索用时 125 毫秒
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根据同步施工网络控制系统的控制原理,分析了时变、随机和不确定的网络时延对同步误差控制所产生的影响。针对传统Smith预估器用于多被控对象同步控制时存在的缺陷与不足进行了分析,提出了一种改进型Smith预估器,实现了对网络时延、被控对象纯滞后因子以及同步误差控制器的多重Smith预估补偿,将其从内部反馈回路中彻底消除,预估模型无需预估与在线测量其大小与变化规律。通过基于控制器局域网络(controller area network,简称CAN)的盾构管片拼装机同步网络控制系统,对常规比例积分微分(proportion integral derivative,简称PID)同步网络控制和基于改进型Smith预估器的PID同步网络控制性能进行了仿真对比分析,并通过实验进行了验证。结果表明,常规PID网络控制同步误差为-3~3mm,基于改进型Smith预估器的PID网络控制同步误差为-1.5~1.5mm,后者可显著提高同步施工网络控制系统的同步控制性能与精度。 相似文献
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针对热轧恒压供水系统的非线性和时滞性特点,提出了一种智能Smith预估多模控制策略。当供水压力差绝对值大于等于设定值的20%时采用了PD控制,在设定值的10%到20%范围内采用PID控制,小于设定值的10%时采用了模糊自适应PID控制,通过模糊规则在线调整PID控制器的三个参数,并引入Smith预估器对供水系统的纯滞后现象进行补偿。基于推导出的典型恒压供水模型,利用MATLAB软件对常规Smith-PID、Smith-模糊PID、智能Smith预估多模控制器进行仿真分析。仿真结果及现场应用表明:相比常规的PID-Smith和Smith-模糊PID控制器,智能Smith预估多模控制器具有鲁棒性强、动态响应快及稳态精度高的优点。 相似文献
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Smith预估器与观测器结合的补偿控制在时滞系统中的应用 总被引:1,自引:0,他引:1
在工业过程中,控制的对象通常具有滞后环节。对于大滞后的被控对象而言,Smith预估补偿控制可以提供很好的控制品质,但前提是必须提供精确的数学模型。为了解决模型失配时Smith预估控制效果不理想这一问题,文章提出了Smith预估器与状态观测器结合的补偿控制策略,通过Smith预估器抵消闭环特征方程中出现的时滞项,利用状态观测器提高了系统的响应速度和系统的稳定性,仿真结果表明该方法的有效性。 相似文献
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改进的Smith预估控制器 总被引:2,自引:0,他引:2
本文在传统Smith预估器的基础上,引入了"参考轨迹"的作法,形成了改进型的Smith预估控制,同时采用模糊PID控制器作为系统控制器.仿真表明这种方法能够克服传统Smith预估器对模型精度敏感的问题,能在设定值扰动、负荷扰动控制中取得满意的控制品质. 相似文献
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基于Smith模糊PID控制算法的炉温控制系统 总被引:6,自引:1,他引:5
针对电加热炉温度控制系统,研究了Smith模糊PID复合控制方法.该控制方法利用Smith预估算法克服纯滞后,利用模糊控制来提高系统的鲁棒性,利用PID控制来提高稳态精度.在模型匹配和失配情况下进行了仿真研究,结果表明复合式控制器具有良好的稳定性和鲁棒性.实际运行结果也表明,对于大时间滞后的电加热炉温控系统是一种实用而简便的控制方法. 相似文献
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串级-Smith预估控制在温度大滞后系统中的应用 总被引:1,自引:0,他引:1
在工业过程中,大滞后系统普遍存在。文章以一实验用加热装置为研究对象,针对该温度控制系统具有大滞后的特点,采用串级控制结构结合Smith预估控制器的控制方案。内环采用Smith预估器,大幅度降低滞后对控制系统动态性能的影响;外环采用PI控制实现系统无静差。实验表明,该种控制系统与单回路PID控制或Smith预估控制相比具有更优的动态特性和鲁棒性。 相似文献
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Application of Smith Predictor Based on Single Neural Network in Cold Rolling Shape Control 总被引:4,自引:0,他引:4
WANG Yiqun SUN FD LIU Jian SUN Menghui XIE Yihan 《机械工程学报(英文版)》2009,22(2):282-286
Flatness is one of the most important criterion factors to evaluate the quality of the steel strip. To improve the strip' s flatness quality, the most frequently used methodology is to employ the closed-loop automatic shape control system. However, in the shape control system, the shape-meter is always installed at the down way of the exit of the cold rolling mill and can not sense the changes of the strip flatness in the rolling gap directly. This kind of installation results in the delay of the feedback in the control system. Therefore, the stability and response performance of the system are strongly affected by the delay. At present, there is still no mature way to design controllers for systems with time delay. Although the conventional PID controller used in most practical applications has the capability to comte the delay, the effect of the compensation is limited, especially for the systems with long time delay. Smith predictor, as a compensator for solving this problem, is now widely used in industry systems. However, the request of highly precise model of the system and the poor adaptive performance to the changes of related parameters limit the application of the Smith predictor in practice. In order to overcome the drawbacks of the Smith predictor, a new Smith predictor based on single neural network PID (SNN-PID) is proposed. Because the single neural network is employed into the Smith predictor to improve the controller's self-adaptability, the adaptive capability to the varying parameters of the system is improved. Meanwhile, for the purpose of solving the problems such as time-consuming and complicated calculation of the neural networks in real time, the learning coefficient of neural network is divided into several stages as usually done in expert control system. Therefore, the control system can obtain fast response due to the improved calculation speed of the neural networks. In order to validate the performance of the proposed controller, the experiment is conducted on the shape control system in a 300 mm four-high reversing cold rolling mill. The experimental results show that the SNN-PID with Smith predictor controller can effectively compeusate the delay effects and achieve better control performance than the conventional PIO controller. 相似文献
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Kaya I 《ISA transactions》2001,40(3):223-234
Many investigations have been done on tuning proportional-integral-derivative (PID) controllers in single-input single-output (SISO) systems. However, only a few investigations have been carried out on tuning PID controllers in cascade control systems. In this paper, a new approach, namely the use of a Smith predictor in the outer loop of a cascade control system, is investigated. The method can be used in temperature control problems where the secondary part of the process (the inner loop) may have a negligible delay while the primary loop (the outer loop) has a time-delay. Two different approaches, including an autotuning method, to find the controller parameters are proposed. It is shown by some examples that the proposed structure as expected can provide better performance than conventional cascade control, a Smith predictor scheme or single feedback control system. 相似文献
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针对温度控制系统的纯滞后的特点,根据电子封装模具温度精确控制的需要,提出了基于Smith预估器和模糊自适应PID控制器的温度控制系统的设计方法。首先,根据阶跃响应建立被控对象的数学模型,然后在被控对象的数学模型的基础上设计出Smith预估器;其次,建立Mamdani模糊模型,实时对增量PID控制器的3个参数进行修正;最后,实现电子封装温度控制的硬件系统和软件系统的设计。该设计解决了纯滞后对控制系统稳定性的不良影响,大大提高了温度控制的精度,并且基于此种方法的硬件系统和软件系统也易于实现,可靠性高,鲁棒性好。 相似文献
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针对视觉延迟的问题,提出采用改进的Smith预估器(MSP)来改善视觉伺服系统的控制品质。在对基于位置的动态"look-and-move" 视觉伺服系统特性分析的基础上,建立了基于MSP视觉伺服系统的结构,同时建立了视觉伺服系统的分时模型。在微操作机器人平台上进行了点到点、抗干扰和微齿轮的跟踪抓取实验。结果表明,与只有PID控制器的视觉伺服系统相比,带MSP的视觉伺服系统具有更好的控制品质。克服了由于图像采集、传输和处理导致的视觉伺服延迟而严重影响控制系统的品质局限,并克服了传统方法通过减小系统增益来增强系统的鲁棒性,但同时降低了系统响应特性的缺点。 相似文献
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针对单神经元自适应PSD的特点,提出一种根据误差的大小而采用不同单神经元控制器结构的算法,分析了其稳定性和收敛性。对基于变结构神经元自适应PSD控制器的非织造布面密度在线控制系统进行了仿真研究与实际应用。结果表明改进后的控制器在稳定性和快速性方面都有很大的改善。 相似文献