共查询到20条相似文献，搜索用时 31 毫秒
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统计过程控制是过程监控与故障诊断的方法。在多变量统计过程控制中,传统的方法主要包括主元分析和偏最小二乘,这些方法存在着诸多缺陷。设计时可以应用非线性主元分析、非线性偏最小二乘、动态主元分析、自适应主元分析、多尺度主元分析等方法进行改进。研究中要重视带噪声的监控模型、过程模型信息与经验知识相结合等问题,同时可以把一些新的降维技术用于统计过程控制中。 相似文献
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CHEN Yue-hua CAO Guang-yi ZHU Xin-jian 《浙江大学学报(A卷英文版)》2007,8(5):748-754
This paper describes a nonlinear model predictive controller for regulating a molten carbonate fuel cell (MCFC). In order to improve MCFC’s generating performance, prolong its life and guarantee safety, it must be controlled efficiently. First, the output voltage of an MCFC stack is identified by a least squares support vector machine (LS-SVM) method with radial basis function (RBF) kernel so as to implement nonlinear predictive control. And then, the optimal control sequences are obtained by applying genetic algorithm (GA). The model and controller have been realized in the MATLAB environment. Simulation results indicated that the proposed controller exhibits satisfying control effect. 相似文献
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In this paper,a hybrid adaptive compensation control scheme is proposed to compensate the friction occurrence and other nonlinear disturbance factors that exist in the high-precision servo system.An adaptive compensation controller with a dual-observer structure is designed,while the LuGre dynamic friction model with non-uniform parametric uncertainties characterizes the friction torque.Considering the influence of the periodic disturbance torque and parametric uncertainties,fuzzy systems and a robust term are employed.In this way,the whole system can be treated as a simple linear model after being compensated,then the proportional-derivative (PD) control law is applied to enhancing the control performance.On the basis of Lyapunov stability theory,the global stability and the asymptotic convergence of the tracking error are proved.Numerical simulations demonstrate that the proposed scheme has potentials to restrain the impact of disturbance and improving the tracking performance. 相似文献
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A new identification method for a linear discrete-time closed-loop system is proposed based on an output over-sampling scheme. When the system outputs are over-sampled the new output sequences would contain more information about the plant structure. Using general least squares method （GLS） the plant over-sampled model should be recognized. Then the original plant model should be obtained by its relationship with the over-sampled model. Compared with conventional approaches the advantage of the new method is that even if the ordinary identifiability conditions are not satisfied, a close-loop system can be identified by using the oversampled output without utilizing any external test signal. Accuracy analysis shows the relationship between the estimation error and the over-sampling rate. Numerical simulation illnstrates its effectiveness. 相似文献
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改进了传统的神经网络BP算法,提出了基于广义BP算法的非线性不确定系统的神经网络模型参考自适应控制方案.并将其用于非线性不确定系统的控制,仿真实验表明了控制器具有良好的非线性控制性能. 相似文献
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针对一类具有饱和非线性输入的混沌系统,基于RBF神经网络的逼近能力提出一种控制方案。该方法利用自适应控制和鲁棒控制,使系统可在模型函数和外扰未知下,设计出结构简单有效的控制器,有效消除了现实中由于饱和非线性输入的存在而引起的控制器抖动的不良控制效果。仿真结果表明了所提控制方法的可行性。 相似文献
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The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality. Partial least squares (PLS) regression model, in which the turbidity and Fe are regarded as con-trol objectives, is used to establish the statistical model. The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data. The percentages of absolute relative error (below 15%, 20%, 30%) are 44.4%, 66.7%, 100% (turbidity) and 33.3%, 44.4%, 77.8% (Fe) on the 4th sampling point; 77.8%, 88.9%, 88.9% (turbidity) and 44.4%, 55.6%, 66.7% (Fe) on the 5th sampling point. 相似文献
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The least means squares (LMS) adaptive filter algorithm was used in active suspension system. By adjusting the weight of adaptive filter, the minimum quadratic performance index was obtained. For two-degree-of-freedom vehicle suspension model, LMS adaptive controller was designed. The acceleration of the sprung mass,the dynamic tyre load between wheels and road,and the dynamic deflection between sprung mass and unsprung mass were determined as the evaluation targets of suspension performance. For LMS adaptive control suspension, compared with passive suspension, acceleration power spectral density of sprung mass acceleration under the road input model decreased 8-10 times in high frequency resonance band or low frequency resonance band. The simulation results show that LMS adaptive control is simple and remarkably effective. It further proves that the active control suspension system can improve both the riding comfort and handling safety in various operation conditions, and the method is fit for the active control of the suspension system. 相似文献
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A new chaos control method is proposed to take advantage of chaos or avoid it. The hybrid Internal Model Control and Proportional Control learning scheme are introduced. In order to gain the desired robust performance and ensure the system's stability, Adaptive Momentum Algorithms are also developed. Through properly designing the neural network plant model and neural network controller, the chaotic dynamical systems are controlled while the parameters of the BP neural network are modified. Taking the Lorenz chaotic system as example, the results show that chaotic dynamical systems can be stabilized at the desired orbits by this control strategy. 相似文献
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INTRODUCTIONOneoftheoldestresearchesofchaosincon trolfieldscanbeseeninthepaperbyKalman(1956) ,whofirstfoundnon synchronousoscil lationsinatwo dimensionalsampled datacontrolsystem .IntheOGYmethoddevelopedbyOttetal.(1990 ) ,chaoticphenomenawaseliminatedbyadjustingparametersofthesystemswhenthechaoticorbitcomesnearaperiodicalorbit.ButtheOGY’smethodrequiresmonitoringthesys temlongenoughtodeterminealinearizationmodeintheneighborhoodofthedesiredunstableperiodicorbitbeforeitcanbeapplied .Besi… 相似文献
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This paper proposes an adaptive algorithm of neural nets with a special perturbation for a real time velocity control system
of a VVVF (Variable Voltage Variable Frequency) hydraulic elevator. The weight vector of the neural network is adaptively
adjusted by the LMS (Least Mean Square) with perturbation, so it is not necessary to know the nonlinear continuous function
of the control system. The nonlinear velocity control system is considered as the controller output function in an adaptive
controller model. The experimental results obtained from the VVVF hydraulic elevator showed that the neural nets controller
using the perturbation algorithm proposed are much stabler and faster in dynamic response compared with the conventional PID
(Proportion-Integration-Derivation) controller.
Project (69775013) Supported by NSFC 相似文献
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Robust adaptive controller design for a class of nonlinear systems with unknown high frequency gains
INTRODUCTIONMany researchers have devoted their energy to the development of nonlinear system with unknown control directions during the past few years. The class of nonlinear system has been developed greatly since Mudgett and Morse (1985) relaxed the assumption that the unknown multiplicative terms are not only sign-invariant but also have known signs. A method called correction vector approach was proposed in (Lozano et al., 1990) and has been applied to design adaptive controller of … 相似文献
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Nonlinear decoupling controller design based on least squares support vector regression 总被引：1，自引：0，他引：1
INTRODUCTION Most practical systems are multivariate nonlin- ear systems. In general, the MIMO (multiple inputs and multiple outputs) systems are coupled. This cou- pling affects the effectiveness of a specific loop con- troller on the corresponding output, and in some case, may become serious and cause many difficulties to the control system design. How to decouple the mul- tivariate systems and design practical controllers is one of the major issues in nonlinear control area. In recen… 相似文献
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Adaptive rotor current control for wind-turbine driven DFIG using resonant controllers in a rotor rotating reference frame 总被引：1，自引：0，他引：1
This paper proposes an adaptive rotor current controller for doubly-fed induction generator （DFIG）, which consists of a proportional （P） controller and two harmonic resonant （R） controllers implemented in the rotor rotating reference frame. The two resonant controllers are tuned at slip frequencies ωslip＋ and ωslip-, respectively. As a result, the positive- and negative-sequence components of the rotor current are fully regulated by the PR controller without involving the positive- and negative-sequence decomposition, which in effect improves the fault ride-through （FRT） capability of the DFIG-based wind power generation system during the period of large transient grid voltage unbalance. Correctness of the theoretical analysis and feasibility of the proposed unbalanced control scheme are validated by simulation on a 1.5-MW DFIG wind power generation system. 相似文献
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基于后推设计方法,Nussbaum函数的性质及积分型李亚普诺夫函数,提出了一种自适应神经网络控制器的设计方案。通过引入示性函数,提出一种简化死区模型,取消了死区模型的倾斜度相等的条件。此外,该方法取消了函数控制增益符号已知和死区模型参数上界、下界已知的条件。理论分析证明了闭环系统是半全局一致终结有界。 相似文献
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提出了一种用于单相有源电力滤波器的全数字式混合电流控制方案．该混合电流控制方案结合无差拍控制以及双模结构重复控制以实现优异的稳态性能和动态特性．区别于传统方案,采用该方案的有源电力滤波器可消除电网中存在的奇次和偶次谐波．给出了该混合电流控制方案的详细设计原则,并进行了稳定性分析．在此基础上,提出了混合电流控制结合谐振控制器的一种优选方案以消除电网中的特定次谐波,并讨论了谐振控制与几种重复控制的内在联系．实验结果验证了电流控制方案在有源电力滤波器中的优点和有效性． 相似文献
19.
To prevent the oxygen starvation and improve the system output performance, an adaptive inverse control (AIC) strategy is developed to regulate the air supply flow of a proton exchange membrane fuel cell (PEMFC) system in this paper.The PEMFC stack and the air supply system including a compressor and a supply manifold are modeled for the purpose of performance analysis and controller design. A recurrent fuzzy neural network (RFNN) is utilized to identify the inverse model of the controlled system and generates a suitable control input during the abrupt step change of external disturbances. Compared with the PI controller, numerical simulations are performed to validate the effectiveness and advantages of the proposed AIC strategy. 相似文献
20.
In order to overcome the low precision and weak applicability problems of the current municipal water network state simulation model, the water network structure is studied. Since the telemetry system has been applied increasingly in the water network, and in order to reflect the network operational condition more accurately, a new water network macroscopic model is developed by taking the auto-control adjusting valve opening state into consideration. Then for highly correlated or collinear independent variables in the model, the partial least squares （PLS） regression method provides a model solution which can distinguish between the system information and the noisy data. Finally. a hypothetical water network is introduced for validating the model. The simulation results show that the relative error is less than 5.2%. indicating that the model is efficient and feasible, and has better generalization performance. 相似文献