A General Robust MPC Design for the State‐Space Model: Application to Paper Machine Process

Applying model predictive control (MPC) in some cases such as complicated process dynamics and/or rapid sampling leads us to poorly numerically conditioned solutions and heavy computational load. Furthermore, there is always mismatch in a model that describes a real process. Therefore, in this paper in order to prevail over the mentioned difficulties, we design a robust MPC using the Laguerre orthonormal basis in order to speed up the convergence at the same time with lower computation adding an extra parameter “a” in MPC. In addition, the Kalman state estimator is included in the prediction model and accordingly the MPC design is related to the Kalman estimator parameters as well as the error of estimations which helps the controller react faster against unmeasured disturbances. Tuning the parameters of the Kalman estimator as well as MPC is another achievement of this paper which guarantees the robustness of the system against the model mismatch and measurement noise. The sensitivity function at low frequency is minimized to tune the MPC parameters since the lower the magnitude of the sensitivity function at low frequency the better command tracking and disturbance rejection results. The integral absolute error (IAE) and peak of the sensitivity are used as constraints in optimization procedure to ensure the stability and robustness of the controlled process. The performance of the controller is examined via the controlling level of a Tank and paper machine processes.     

Closed-loop identification using direct approach and high order ARX/GOBF-ARX models

Model accuracy plays a key role in the performance of advanced, model predictive control algorithms. Model fidelity is usually affected by routine operating condition changes, which necessitate reidentification. From several theoretical and practical considerations, it is recommended that such re-identification be performed under closed-loop conditions. The direct approach for closed-loop identification, owing to its simplicity, is better suited for MPC. In order to yield unbiased and consistent parameter estimates, however, this approach requires the noise model to be sufficiently parameterized. Towards this objective, high order ARX models are the most suitable candidates from the viewpoint of ease of parameter estimation. For multivariable systems, however, the identification of high order ARX models would require longer experiments to be performed. This being undesirable from a practical viewpoint, there is a need for a parsimonious parameterization that would retain the benefits of high order ARX models. In this work, we propose to use generalized orthonormal basis filters (GOBFs) to achieve this parsimonous parameterization. Further, we propose an approach to obtain reduced order models by emphasizing important frequencies so as to suitably shape the bias. We also show that the choice of the GOBF parameterization has another important merit, viz. their ability to perform well even with minimal perturbation data or short experiment times. The efficacy of the proposed approach is demonstrated via simulations on the benchmark Shell Control Problem and a laboratory quadruple tank setup.     

关于Grünwald插值算子的L_p收敛速度

本文给出了以第二类Tchebyshev多项式的零点为插值结点的Grunwald插值多项式在Lp范数下的收敛速度估计,并证明了该估计在1≤p<2时是精确的。     

紧支集正交子波的构造及其应用

介绍了紧支集子波的特性,详细讨论 Ｄａｕｂｅｃｈｉｅｓ 子波的构造方法并给出应用实例。说明子波变换用于系统响应信号的分析是十分有效的。     

基于离散插值样条的提升小波变换

文中引入了一种对信号递归滤波的提升方法,该方法与通常的提升方法不同之处是使用IIR滤波器.探讨了空间域中基于离散插值样条的预测算子和更新算子的设计.提出的方法以插值为基础,只涉及信号的采样,不要求使用正交公式,更适合信号的处理.最后由数值仿真验证了该算法的性能,对于软阈值法小波系数去噪,提升小波变换T12同B9/7相比,前者略优于后者,提升方法的优点在于其设计上的灵活性和计算花费少.     

一种构造正交小波基的新方法

给出了不须验证多尺度分析条件的正交尺度函数新的构造定理，并进行了证明。由此导出了正交小波基构造方法，并给出了一个构造实行。     

伯努利卷积下正交基的推广

考虑了伯努利卷积下λ=p/（2n）的情形,应用转移算子证明了对于某些正整数k0,E（pk0Γ）是L2（pμ/（2n））的正交基,那么对于任意的正整数k,E（pkΓ）也是正交基.     

CuBr激光器放电回路参数优选的正交设计实验

为使CuBr蒸气激光器的工作状态最佳(稳定且高效),利用正交设计实验方法对其放电回路参数实行最佳搭配实验,得到了一组放电回路参数,可使CuBr蒸气激光器工作在最佳状态。     

电离层电子密度剖面EoFs解析研究

离子密度随高度的解析展开是电离层物理模式参数研究中的一个关键技术.用经验正交函数分析了(EoFs)电离层电子密度剖面解析中的应用,研究并给出了利用EoFs进行电离层电子密度剖面解析展开和剖面重构的算法.以海口站(20°N,110.3°E)为例,给出了电子密度剖面解析与重构算法的应用实例,分析结果表明数值解析的重构剖面与模式计算结果有很好的一致性.     

Improved Solution of the Neutron Diffusion Equation Using Wavelet Theory

The development of the fast reactor (FR) cycle is being advanced to utilize plutonium and transuranium (TRU) in Japan. In the fabrication process, it is considered that a fuel pin spirally wrapped with a thin wire is laid horizontally. Then, cooling air flows vertically from the bottom side into the gap of the pin bundle so as to suppress the temperature increase due to decay heat. From the viewpoint of safety assessment during the fabrication, a thermal hydraulic analysis method plays an important role in investigating the maximum temperature and the temperature distribution of the fuel pins. In the present paper, a subchannel analysis tool has been developed. Using the developed tool, the benchmark analysis of the mocked up experiment has been carried out, as well as the numerical investigation of a multidimensional effect of fuel cladding thermal conductivity on the maximum temperature. It is demonstrated that the multidimensional effect of the cladding thermal conductivity is not negligible in the analysis. A good agreement is achieved in the case of a comparatively large clearance size between the side wall and the pin bundle when one considers a natural convection heat transfer at the outermost boundary with a comparatively low computational cost.