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针对一类离散时间非线性被控对象,根据模型参数的变化范围,对被控对象建立多个模型,并针对每一模型设计控制器.基于模型的估计误差建立指标切换函数,每一采样时刻,利用指标切换函数选择最优模型,并将基于此模型的控制器切换为当前控制器.采用局部化技术,保证在不损失控制品质的同时,减少多模型自适应控制器的计算量.可以证明,多控制器相互切换时闭环系统是稳定的,同时由于多个模型的存在,控制品质得到了极大的改善. 相似文献
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基于动态模型库的多模型切换控制 总被引:4,自引:0,他引:4
针对含有有界扰动和模型参数跳变的离散时间系统,提出基于动态模型库的多模型切换控制方法.在模型参数范围未知情况下,利用在线学习的多模型自适应控制算法自动建立多模型,并对模型库中的子模型进行优化.采用具有积分特性的指标函数作为切换准则.在每一采样时刻根据其最小值来选择与实际系统最接近的模型,并将基于此模型的控制器切换为当前控制器.文中证明了该算法能够保证闭环系统的稳定性和跟踪误差的渐近收敛性.计算机仿真结果表明该算法的有效性. 相似文献
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基于不同加权因子的随机多模型自适应控制 总被引:1,自引:1,他引:0
针对一类噪声方差未知的随机系统,基于不同加权因子设计多个参数辨识器辨识模型参数,在此基础上,构成多模型自适应控制器.在每个采样时刻基于指标切换函数选择最佳辨识模型.并将基于此最佳模型设计的控制器切换为当前控制器.同时,证明了多个模型控制器之间相互切换时整个闭环系统是全局收敛的.仿真结果表明,同单一自适应模型控制器相比,这种基于多个不同加权因子的多模型自适应控制器在模型参数发生跳变时可很好地改善被控对象的控制品质. 相似文献
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基于分片线性化方法辨识一类非线性系统,给出了非线性系统的多线性模型表示。基于线性模型建立多个控制器,基于最大最小指标切换函数构成多模型自适应控制器。给出了非线性系统多模型自适应控制算法的优化模型集建立方法,解决了多模型自适应控制模型多、计算最大的问题。仿真结果证明了算法的有效性。 相似文献
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传统鲁棒自适应控制由于考虑了实际系统存在的不确定性,在一定程度上扩大了常规自适应控制的应用范围,但是传统鲁棒自适应控制大多只是从系统全局稳定性的角度出发来设计控制器而忽略系统动态和稳态性能,导致其无法在工况多变的实际被控系统中取得令人满意的效果。针对传统鲁棒自适应控制的不足,本文对由ARMA模型描述并包含未建模动态的系统设计了多模型鲁棒自适应控制器。首先采用正则化技术将系统未建模动态转化为系统有界扰动,并在系统降阶模型的基础上根据系统工况的变化设计了多个固定控制器和2个鲁棒自适应控制器,并根据性能指标函数选择最佳控制器作为当前系统控制器以提高系统性能。仿真实验说明当系统存在未建模动态以及系统工况发生变化时,本文设计的控制器能获得较好的控制效果。 相似文献
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Karlene A. Kosanovich James G. Charboneau Michael J. Piovoso 《Journal of Process Control》1997,7(1):43-56
A hybrid, dynamical supervisory control strategy is introduced to control multi-product processes. The scheme involves the selection of the best setpoint controller, from an existing family of feedback controllers, to be placed into feedback with the process so as to cause the output to track the desired setpoint. This task is performed without exhaustive trial and error, by minimizing a specific normed output estimation error that relates the process output to a shared controller state. The performance of the supervisory control strategy is demonstrated on a continuous-stirred tank reactor that can be operated at three different conversion levels. However, the most desirable operating point is open-loop unstable. Linear controllers are designed for each operating region and the role of the supervisory control strategy will be to determine the switching logic as different scheduling policies are demanded. 相似文献
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一种基于DMC的新型预测PID控制器及其整定(英文) 总被引:1,自引:0,他引:1
本文提出一种基于动态矩阵控制(DMC)算法预测特性的新型PID控制方法.在考虑将来的输出期望偏差罚函数最小的前提下,由DMC计算出控制变量的值.继而构造基于DMC的预估器用以预测将来时刻的系统输出.根据将来时刻的多步预测偏差,PID控制器产生当前时刻的实际控制增量.文中也给出了基于DMC的预估器及PID控制器的参数整定方法.仿真结果表明,与常规的PID控制和DMC控制相比,所提方法具有良好的控制性能,扰动抑制尤其优良. 相似文献
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多变量动态矩阵控制系统的闭环稳定性 总被引:1,自引:1,他引:0
定量分析了无约束多输入多输出(MIMO)动态矩阵控制系统的闭环稳定条件,首先基于脉冲响应模型重新描述了动态矩阵控制(DMC)算法;在此基础上,推导得到了MIMODMC系统的闭环稳定条件,以便于预测控制系统的分析与设计。 相似文献
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质子交换膜燃料电池动态建模及其双模控制 总被引:2,自引:1,他引:1
由于已提出的质子交换膜燃料电池(PEMFC)模型难于控制, 提出利用MATLAB/SIMULINK仿真工具进行PEMFC系统动态建模, 同时为实现对PEMFC系统输出电压的控制, 采用了基于模糊规则切换的模糊逻辑控制器(FLC)和比例积分微分控制器(PID)相结合的双模控制方式. 仿真结果证明该动态模型易于控制, 能够反映出PEMFC系统的动态输出特性, 而且验证了基于模糊规则切换的双模控制能够有效抑制扰动, 改善PEMFC系统的动态输出特性, 保证系统的稳定运行, 有助于对PEMFC系统的输出性能分析以及实时控制系统的设计. 相似文献
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SISO动态矩阵控制的鲁棒稳定性条件 总被引:9,自引:1,他引:8
定量分析了单输入单输出(SISO)动态矩阵控制系统的鲁棒稳定条件,采用脉冲响
应模型簇来描述被控过程的不确定性,并讨论了基于脉冲响应模型(FIR)的动态矩阵控制
(DMC)算法;在此基础上,推导了DMC闭环系统的鲁棒稳定条件. 相似文献
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This paper deals with the problem of fault‐tolerant control (FTC) for a class of nonlinear uncertain systems against actuator faults using adaptive logic‐based switching control method. The uncertainties under consideration are assumed to be dominated by a bounding system which is linear in growth in the unmeasurable states but can be a continuous function of the system output, with unknown growth rates. Several types of common actuator faults, e.g., bias, loss‐of‐effectiveness, stuck and hard‐over faults are integrated by a unified fault model. By utilizing a novel adaptive logic‐based switching control scheme, the actuator faults can be detected and automatically accommodated by switching from the stuck actuator to the healthy or even partly losing‐effectiveness one with bias, in the presence of large parametric uncertainty. In particular, two switching logics for updating the gain in the output feedback controllers are designed to ensure the global stability of the nominal (fault‐free) system and the boundedness of all closed‐loop signals of the faulty system, respectively. Two simulation examples of an aircraft wing model and a single‐link flexible‐joint robot are given to show the effectiveness of the proposed FTC controller. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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动态矩阵控制(DMC)是基于对象阶跃响应的一种预测控制算法,它具有结构清晰、算法简单、对模型失配适应能力强等优点,适用于纯时滞,开环渐近稳定的线性对象,是一种成功而有效的控制算法。但DMC的输出动态特性受其参数的影响,目前,对DMC参数的选取一般都是采用试凑结合仿真的方法,费时又费力,从而给设计者造成很大的困难。该文提出了一种对DMC的改进方法——DMPIDC,使PID参数整定方法与动态矩阵控制结合起来.用整定出的PID参数作为DMPIDC的加权系数,保证了良好的输出动态特性,仿真结果表明这种方法是可行的。 相似文献
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Nael H. El-Farra Prashant Mhaskar Panagiotis D. Christofides 《Systems & Control Letters》2005,54(12):1046-1182
This work presents a hybrid nonlinear control methodology for a broad class of switched nonlinear systems with input constraints. The key feature of the proposed methodology is the integrated synthesis, via multiple Lyapunov functions, of “lower-level” bounded nonlinear feedback controllers together with “upper-level” switching laws that orchestrate the transitions between the constituent modes and their respective controllers. Both the state and output feedback control problems are addressed. Under the assumption of availability of full state measurements, a family of bounded nonlinear state feedback controllers are initially designed to enforce asymptotic stability for the individual closed-loop modes and provide an explicit characterization of the corresponding stability region for each mode. A set of switching laws are then designed to track the evolution of the state and orchestrate switching between the stability regions of the constituent modes in a way that guarantees asymptotic stability of the overall switched closed-loop system. When complete state measurements are unavailable, a family of output feedback controllers are synthesized, using a combination of bounded state feedback controllers, high-gain observers and appropriate saturation filters to enforce asymptotic stability for the individual closed-loop modes and provide an explicit characterization of the corresponding output feedback stability regions in terms of the input constraints and the observer gain. A different set of switching rules, based on the evolution of the state estimates generated by the observers, is designed to orchestrate stabilizing transitions between the output feedback stability regions of the constituent modes. The differences between the state and output feedback switching strategies, and their implications for the switching logic, are discussed and a chemical process example is used to demonstrate the proposed approach. 相似文献