共查询到20条相似文献,搜索用时 15 毫秒
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《Journal of Process Control》2014,24(11):1710-1719
This paper presents a new tuning methodology of the main controller of an internal model control structure for n × n stable multivariable processes with multiple time delays based on the centralized inverted decoupling structure. Independently of the system size, very simple general expressions for the controller elements are obtained. The realizability conditions are provided and the specification of the closed-loop requirements is explained. A diagonal filter is added to the proposed control structure in order to improve the disturbance rejection without modifying the nominal set-point response. The effectiveness of the method is illustrated through different simulation examples in comparison with other works. 相似文献
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本文在一般预测控制的基础之上,对于两种特殊的系统分别提出了对应的预测控制算法,仿真效果表明了这两种算法的正确性和实用性。 相似文献
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For nonlinear thermal power plants whose dynamics vary with load demand, a load-dependent exponential ARX (Exp-ARX) model, which can effectively describe the nonlinear properties of the plants, is presented. The Exp-ARX model requires only off-line identification. Based on the model, a constrained multivariable generalized predictive control (CMGPC) strategy is designed and implemented in a simulation of 375 MW thermal power plants. This CMGPC algorithm does not resort to on-line parameter estimation and can more exactly predict the future outputs of the nonlinear plants, so it shows better reliability and control performance than the usual GPC algorithm. 相似文献
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This note provides a solution to the constrained command tracking problem using reference governors for a class of continuous-time second order linear systems with an input delay and with pointwise-in-time state and control constraints. The reference governor modifies the command to a closed-loop system based on the prediction of whether the system response to constant commands violates the specified constraints. The solution relies on classical control results for second order linear systems and requires only checking whether predicted outputs violate the constraints at a small number of time instants (e.g., four time instants in the single output case). This greatly simplifies the online computation, especially when a reference governor is applied to system models that are (slowly) changing in time. The effectiveness of the proposed method is demonstrated by a numerical example. 相似文献
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Multiple models and neural networks based decoupling control of ball mill coal-pulverizing systems 总被引:2,自引:0,他引:2
Using a ball mill coal-pulverizing system as a motivating/application example, a class of complex industrial processes is investigated in this paper, which has strong couplings among loops, high nonlinearities and time-varying dynamics under different operation conditions. Focusing on such processes, an intelligent decoupling control method is developed, where the effects of nonlinearities are dealt with by neural network compensations and coupling effects are handled by specifically designed decoupling compensators, while the effect of time-varying dynamics is treated by a switching mechanism among multiple models. The stability and convergence of the closed-loop system are analyzed. The proposed method has been applied to the ball mill coal-pulverizing systems of 200 MW units in a heat power plant in China. Application results show that the system outputs are maintained in desired scopes, the electric energy consumption per unit coal has been reduced by 10.3%, and the production rate has been increased by 8%. 相似文献
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This study proposes an optimal control scheme for the coordinated control system (CCS) of an ultra-supercritical unit. This scheme utilizes a stair-like predictive control algorithm as the core to solve fundamentally the control problem of large delay and inertia in boiler combustion and integrates the feedforward and decoupling control concepts to preserve the traditional control experience. This study aims to provide technical support for the clean and efficient use of coal and the large-scale consumption of renewable energy sources in China. Non-real-time and real-time simulation results show that the scheme can achieve optimal control for each controlled variable, especially in the decoupling control mode; moreover, the fluctuation of each controlled variable is considerably reduced, and the adjustment of each control variable is stable, thereby improving the stability and anti-interference capability of the CCS. From the perspective of practical application of engineering, the research results have been directly productized and applied to practical engineering, the engineering application shows that the control performance is basically consistent with the simulation, the response rate of the unit is considerably increased, and the fluctuation of main steam pressure and mid-point temperature is considerably reduced. In this case, the proposed scheme can guarantee the safety, stability, economy, and flexibility of the unit operation. 相似文献
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人工鱼群算法优化的PID神经网络解耦控制 总被引:3,自引:0,他引:3
针对多变量系统解耦控制的要求和特点,传统的PID神经网络在选取初始权值难以确定,往往是随机得到,容易导致采用的BP学习算法陷入局部极值.提出了一种人工鱼群算法优化PID神经网络初始权值.通过对多变量控制对象的mat-lab仿真验证,把人工鱼群算法优化得到的最优初始权值带入PID神经网络,结果显示加快了PID神经网络的收敛速度,使控制量迅速地接近控制目标,保证了系统稳定性,取得了满意的控制效果. 相似文献
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介绍了自行设计的一套解耦控制实验系统的硬件构成和软件设计,模块式硬件结构简单灵活、安全可靠,基于labVIEW开发平台的人机界面友好、操作方便,大大简化了系统开发过程,并使该系统具有了工程应用意义。最后给出了基于该系统的一例控制结果。 相似文献
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The iterative method labelled correlation-based tuning (CbT) is considered in this paper for tuning linear time-invariant multivariable controllers. The approach allows one to tune some elements of the controller transfer function matrix to satisfy the desired closed-loop performance, while the other elements are tuned to mutually decouple the closed-loop outputs. Decoupling is achieved by decorrelating a given reference with the non-corresponding outputs. The controller parameters are calculated either by solving a correlation equation (decorrelation procedure) or by minimizing a cross-correlation function (correlation reduction). In addition, the preferred way of exciting a 2×2 system for CbT is investigated via the accuracy of the estimated controller parameters. It is shown that simultaneous excitation of both reference signals does not improve the accuracy of the estimated controller parameters compared to the case of sequential excitation. In fact, one must choose between low experimental cost (simultaneous excitation) and better accuracy of the estimated parameters (sequential excitation). The theoretical results are illustrated via three simulation studies. 相似文献
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Michio Kono 《Systems & Control Letters》1983,3(6):349-354
This paper considers decoupling control of time-delay systems. We assume a new decoupling condition which is stronger than the one obtained until now and R[σ]-controllability. Then, a dynamic compensator to achieve decoupling and arbitrary coefficient assignment is presented. 相似文献
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In this note, a procedure is presented to design a multivariable system to achieve arbitrary pole-placement, decoupling, asymptotic tracking and disturbance rejection. The procedure is a modification of the one in [1]. The total degree of compensators required in this design is generally smaller than the one there. 相似文献
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Manuel A. Duarte-Mermoud Alejandro M. Suárez Danilo F. Bassi 《Neural computing & applications》2006,15(1):18-25
The behavior of a multivariable predictive control scheme based on neural networks applied to a model of a nonlinear multivariable real process, consisting of a pressurized tank is investigated in this paper. The neural scheme consists of three neural networks; the first is meant for the identification of plant parameters (identifier), the second one is for the prediction of future control errors (predictor) and the third one, based on the two previous, compute the control input to be applied to the plant (controller). The weights of the neural networks are updated on-line, using standard and dynamic backpropagation. The model of the nonlinear process is driven to an operation point and it is then controlled with the proposed neural control scheme, analyzing the maximum range over the neural control works properly. 相似文献