共查询到19条相似文献,搜索用时 589 毫秒
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任林 《计算机测量与控制》2012,20(1):81-84
针对单容液位系统紊流时的非线性特征,研究了基于RBF-ARX模型预测控制策略控制单容液位系统;讨论RBF-ARX模型结构的选取,模型参数辨识,RBF参数优化,基于RBF-ARX模型的预测控制策略等问题;模型的仿真结果,证实了RBF-ARX模型在非线性系统建模和辨识中的有效性;同基于全局线性ARX模型的预测控制器和PID控制器相比较,基于此模型的预测控制取得了优异的控制效果。 相似文献
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针对无法从工业过程中获得准确状态空间模型的问题,提出一种基于子空间辨识的状态空间模型预测控制方法。利用子空间辨识方法得到的状态空间模型作为系统模型,给出约束条件下的预测控制算法。以CD播放器机械臂系统为例,通过状态空间模型预测控制方法实现对系统输出的跟踪控制,仿真结果表明,该方法控制效果良好。 相似文献
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针对工业过程中普遍存在的非线性被控对象,提出了一种基于支持向量机(SVM)逆系统的广义预测控制算法。该方法根据广义预测控制基于预测模型的特点,将基于支持向量机系统辨识的方法应用于逆系统构建和广义预测控制。该方法利用SVM强大的非线性映射能力离线辨识被控非线性系统的α阶逆模型,并将辨识出的逆模型连接在原被控统之前形成一个α阶纯延时伪线性系统。然后采用广义预测控制(GPC)算法实现对构造出的伪线性系统的预测控制。仿真实验表明了该算法的有效性和优越性。 相似文献
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基于神经网络的广义非线性预测PID控制 总被引:3,自引:0,他引:3
针对一些复杂的非线性系统用基于线性模型的预测控制器控制效果不理想的问题,本文提出在利用前馈网络对非线性系统建模的基础上,对系统输出实现递推多步预测,并且结合非线性PID,用另一前馈神经网络作为控制器,实现对非线性系统的控制。经网络的在线辨识采用梯度法,仿真实验验证了方法的有效性。 相似文献
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Nonlinear one-step-ahead control using neural networks: Control strategy and stability design 总被引:13,自引:0,他引:13
A nonlinear one-step-ahead control strategy based on a neural network model is proposed for nonlinear SISO processes. The neural network used for controller design is a feedforward network with external recurrent terms. The training of the neural network model is implemented by using a recursive least-squares (RLS)-based algorithm. Considering the case of the nonlinear processes with time delay, the extension of the mentioned neural control scheme to d-step-ahead predictive neural control is proposed to compensate the influence of the time-delay. Then the stability analysis of the neural-network-based one-step-ahead control system is presented based on Lyapunov theory. From the stability investigation, the stability condition for the neural control system is obtained. The method is illustrated with some simulated examples, including the control of a continuous stirred tank reactor (CSTR). 相似文献
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一种改进的神经网络非线性预测控制 总被引:1,自引:0,他引:1
从建立神经网络非线性预测模型出发,针对BP网络存在收敛速度慢,容易陷入局部最小的缺点,该文在BFGS拟牛顿法的基础上,提出了一种基于并行拟牛顿优化算法的并行拟牛顿神经网络。该并行拟牛顿优化算法采用两个含有不同参数的拟牛顿校正公式,在每次迭代过程中,利用这两个不同的校正公式得到相应的搜索方向,并通过不精确搜索法求取最优步长,最后根据一性能指标取最优的一个搜索方向和相应的步长对网络各层之间的权值进行修正。Matlab仿真结果表明,同BP神经网络和BFGS拟牛顿神经网络相比,该神经网络具有收敛速度快、模型精度高的特点,更适合于实时非线性控制。 相似文献
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This paper proposes a method for adaptive identification and control for industrial applications. The learning of a T–S fuzzy model is performed from input/output data to approximate unknown nonlinear processes by a hierarchical genetic algorithm (HGA). The HGA approach is composed by five hierarchical levels where the following parameters of the T–S fuzzy system are learned: input variables and their respective time delays, antecedent fuzzy sets, consequent parameters, and fuzzy rules. In order to reduce the computational cost and increase the algorithm’s performance an initialization method is applied on HGA. To deal with nonlinear plants and time-varying processes, the T–S fuzzy model is adapted online to maintain the quality of the identification/control. The identification methodology is proposed for two application problems: (1) the design of data-driven soft sensors, and (2) the learning of a model for the Generalized predictive control (GPC) algorithm. The integration of the proposed adaptive identification method with the GPC results in an effective adaptive predictive fuzzy control methodology. To validate and demonstrate the performance and effectiveness of the proposed methodologies, they are applied on identification of a model for the estimation of the flour concentration in the effluent of a real-world wastewater treatment system; and on control of a simulated continuous stirred tank reactor (CSTR) and on a real experimental setup composed of two coupled DC motors. The results are presented, showing that the developed evolving T–S fuzzy model can identify the nonlinear systems satisfactorily and it can be used successfully as a prediction model of the process for the GPC controller. 相似文献
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基于远程预报辨识的非线性广义预测控制算法 总被引:5,自引:0,他引:5
推导了基于远程预报辨识的非线性广义预测控制算法.该算法在辨识基于Hammer-stein
模型的非线性过程时,采用了预测控制算法中远程预报的思想,并在广义预测控制器的设
计上采用了新的优化指标,这就使辨识机制与控制机制有机地结合起来,对系统的阶次不确定
有很好的鲁棒性. 相似文献
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基于支持向量机的激光焊接过程辨识与控制 总被引:1,自引:1,他引:0
激光焊接过程数学模型足一个较强非线性的数学模型,通常的线性辨识方法无法得到它精确的数学模型.支持向量机作为一种新的机器学习方法,具有较强的非线性拟合能力,应用支持向量机非线性系统回归建模方法,辨识出具有典型非线性特性的焊接过程模型,并采用预测控制算法对焊接过程进行控制.实验证明,支持向量机对非线性系统具有很好的拟合效果,基于支持向量机的预测控制具有较好的非线性控制效果. 相似文献
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《Journal of Process Control》2014,24(1):48-56
This work studies k-step-ahead prediction error model identification and its relationship to MPC control. The use of error criteria in parameter estimation will be discussed, where the identified model is used in model predictive control (MPC). Assume that the model error is dominated by the variance part, it can be shown that a k-step-ahead prediction error model is not optimal for k-step-ahead prediction. A normal one-step-ahead prediction error criterion will be optimal for k-step-ahead prediction. Then it is argued that even when some bias exists, the result could still hold true. Therefore, for MPC identification of linear processes, one-step-ahead prediction error models fever k-step-ahead prediction models. Simulations and industrial testing data will be used to illustrate the idea. 相似文献
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针对未知参数系统的自适应预测函数控制,模型尚未辨识完成或外界干扰造成的模型不准确,会严重影响控制效果,并产生较大的超调和波动.由此,提出一类对偶自适应预测函数控制(Dtml Adaptive Predictive Function Control,DAPFC)算法.在模型辨识的过程中,通过辨识误差的大小,利用对偶控制方法来调整原有自适应控制律,尽可能地获取未知参数信息并抑制由于模型失配造成的控制量的波动.改善了系统在模型失配时的控制效果,并具有较强的鲁棒性.仿真结果表明,该算法具有良好的控制品质. 相似文献