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对一类非线性系统提出一种新的模糊自适应控制方法．此方法用模糊逻辑系统逼 近未知函数,用自适应调节的方法来修正模糊逻辑系统的输入,以此对逼近误差进行补偿,文 中证明了该方法不但能保证闭环系统稳定,而且可使跟踪误差收敛于原点,仿真结果验证了此 方法的有效性。 相似文献
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一类非线性系统的自适应模糊滑模控制 总被引：2，自引：0，他引：2
针对一类不确定非线性系统提出了一种自适应模糊控制方法。该方法用模糊逻辑系统(FLS)逼近理想控制器；用滑模补偿控制器(SMCC)全局补偿逼近误差和系统的不确定性并消除外部干扰的影响，能够保证闭环系统全局渐近稳定，跟踪误差收敛到原点的邻域内。在闭环系统的稳定性分析中取消了文[1-4]中要求的逼近误差平方可积的条件。 相似文献
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孙多青 《河北职业技术师范学院学报》2001,15(4):41-46
对高阶非线性系统设计了模糊直接自适应控制器。用高木－关野型模糊系统作为控制器，用鲁棒控制项对未知的逼近误差进行补偿以减小逼近误差对跟踪精度的影响。所给方法不但能保证闭环系统稳定而且可使跟踪误差收敛到原点或其小邻域内，此外还克服了外界干扰对系统误差的影响。 相似文献
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研究了一类连续时间Takagi-Sugeno模糊系统的镇定控制器设计问题,提出了一种新的基于模糊Lya-punov函数和阶梯隶属度函数的系统镇定条件.通过阶梯隶属度函数逼近原系统的隶属度函数,系统隶属度函数信息被引入到其镇定设计中,从而大大降低了现有T-S模糊控制系统镇定设计的保守性.与已有基于模糊Lyapunov函数的连续T-S模糊系统的镇定设计不同,所提出的镇定条件不依赖于隶属度函数的导数,因此具有较少保守性.此外,所得镇定条件可表示为一组线性矩阵不等式,而不是双线性矩阵不等式,因而可以利用凸优化算法方便地进行求解.仿真实例表明了所提方法的有效性. 相似文献
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胡翔云 《孝感职业技术学院学报》2007,10(1):92-93,76
列表曲线上离散点的数值一般是通过测量或实验得到的.为便于数控编程,必须首先构造出一次逼近函数.逼近函数的构造方法较多,各有其优缺点.采用何种逼近函数要考虑离散点的测量精度及轮廓允许误差要求. 相似文献
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林杰 《福建工程学院学报》2008,6(6)
给出用双圆弧样条逼近带误差空间点列的方法。先在误差范围内用三次B样条曲线逼近带误差的点列,接着把．最列投影到B样条曲线上求得切向,最后采用最长步长算法,生成双圆弧样条逼近该点列。该方法能在给定误差限内以尽量少的双圆弧段数逼近带误差点列,对大挠度的点列逼近也适用。 相似文献
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张爱武 《周口师范学院学报》2013,30(2):1-5
由于模糊数往往可以用梯形模糊数来逼近,因此对梯形模糊数的模糊回归模型的研究就有一定的实用价值.采用最小二乘的方法,针对应用广泛的输入为确定数、输出为梯形模糊数的一元模糊线性回归模型,讨论了该模型回归系数的最小二乘估计和误差项.当梯形模糊数退化为精确数时,该估计就是传统的最小二乘估计.数值模拟和实例研究说明了本文提出的参数估计方法的拟合度比较好. 相似文献
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给出了两种神经网络设计方法,通过用这两种方法解决同一个问题,从而说明了BP算法相对于RBF算法比较粗糙,误差也比较大;而RBF算法训练简洁且学习收敛速度快,能够逼近任意非线性函数． 相似文献
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The operating temperature of a solid oxide fuel cell （SOFC） stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative （PID） control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC. 相似文献
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吴力荣 《河北职业技术学院学报》2010,(1)
给出模糊判断矩阵的一种标度,利用模糊均值、模糊偏差和模糊综合数,结合Satty的特征根法,提出三角模糊数互反判断矩阵的一种排序方法,并通过算例说明该方法的可行性和有效性。 相似文献
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借助于最优逼近理论, 证明了线性SISO TS模糊系统可以逼近任意一个多项式, 然后以Weierstrass逼近定理为桥梁, 证明了该模糊系统可以以任意精度逼近一个任意的连续函数, 从而得到了该模糊系统万能逼近性的一个新的充分条件. 并在证明过程中, 得到了要达到所要求的逼近精度所需的输入模糊集的下确界. 然后从理论上将所得的结果与现有文献中的结果进行了比较, 证明了该结果所需的输入模糊集的数目要少得多, 从而可以简化模糊系统的设计. 最后举例证明了该结论的有效性. 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ,ｏｒｔｈｏｇｏｎａｌｐｏｌｙｎｏｍｉａｌｓａｎｄｆｕｎｃｔｉｏｎｓｄｅｖｅｌｏｐｅｄｂｙＣｈａｎｇｅｔａｌ.( 1 986)ｈａｖｅｂｅｅｎｓｕｃｃｅｓｓｆｕｌｌｙａｐｐｌｉｅｄｉｎｔｈｅｆｉｅｌｄｏｆｄｙｎａｍｉｃｓｙｓｔｅｍｓ,ｆｏｒａｎａｌｙｓｉｓａｎｄｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆｌｉｎｅａｒｓｙｓｔｅｍｓａｎｄｔｈｅｏｐｔｉｍａｌｃｏｎｔｒｏｌ (Ｔｓａｙｅｔａｌ.,1 987) .Ｔｈｅｍａｉｎａｄｖａｎｔａｇｅｏｆｔｈｉｓｔｅｃｈｎｉｑｕｅｉｓｔｈｅ… 相似文献
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The seed method is used for solving multiple linear systems A^(i) x^(i) = b^(i) for l≤ i≤ s , where the coefficient matrix A^(i) and the right-hand side b^(i) are different in general. It is known that the CG method is an effective method for symmetric coefficient matrices A^(i) . In this paper, the FOM method is employed to solve multiple linear systems when coefficient matrices are non-symmetric matrices. One of the systems is selected as the seed system which generates a Krylov subspace, then the residuals of other systems are projected onto the generated Krylov subspace to get the approximate solutions for the unsolved ones. The whole process is repeated until all the systems are solved. 相似文献
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WANG Zhou-jing QIAN Edward Y. 《浙江大学学报(A卷英文版)》2007,8(4):644-650
A vague-set-based fuzzy multi-objective decision making model is developed for evaluating bidding plans in a bid- ding purchase process. A group of decision-makers (DMs) first independently assess bidding plans according to their experience and preferences, and these assessments may be expressed as linguistic terms, which are then converted to fuzzy numbers. The resulting decision matrices are then transformed to objective membership grade matrices. The lower bound of satisfaction and upper bound of dissatisfaction are used to determine each bidding plan’s supporting, opposing, and neutral objective sets, which together determine the vague value of a bidding plan. Finally, a score function is employed to rank all bidding plans. A new score function based on vague sets is introduced in the model and a novel method is presented for calculating the lower bound of sat- isfaction and upper bound of dissatisfaction. In a vague-set-based fuzzy multi-objective decision making model, different valua- tions for upper and lower bounds of satisfaction usually lead to distinct ranking results. Therefore, it is crucial to effectively contain DMs’ arbitrariness and subjectivity when these values are determined. 相似文献
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《Structural equation modeling》2013,20(2):153-185
Meta-analytic structural equation modeling (MA-SEM) is increasingly being used to assess model-fit for variables' interrelations synthesized across studies. MA-SEM researchers have analyzed synthesized correlation matrices using structural equation modeling (SEM) estimation that is designed for covariance matrices. This can produce incorrect model-fit chi-square statistics, standard error estimates (Cudeck, 1989), or both for parameters that are not scale free or that describe a scale-noninvariant model unless corrected SEM estimation is used to analyze the correlations. This study introduced univariate and multivariate approximate methods for synthesizing covariance matrices for use in MA-SEM. A simulation study assessed the approximate methods by estimating parameters in a scale-noninvariant model using synthesized covariances versus synthesized correlations with and without the appropriate corrections. Standard error bias was noted only for uncorrected analyses of pooled correlations. Chi-square model-fit statistics were overly conservative except when covariance matrices were analyzed. Benefits and limitations of this approximate method are presented and discussed. 相似文献
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周彩根 《连云港职业技术学院学报》2005,18(3):25-27
对一类具有不确定性的非线性系统，根据滑模控制原理并利用T-S模糊系统的逼近能力，提出了一种自适应模糊滑模控制系统的设计方法。控制结构中采用模糊系统自适应补偿过程的不确定性，利用Lyapunov理论，证明了控制算法是全局稳定的，跟踪误差可收敛到零的一个邻城内。 相似文献
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张平安 《深圳信息职业技术学院学报》2006,4(4):29-31
本文提出了一种新的用于复杂系统建模的模糊模型,并从理论上分析证明,该模型可表示任何一个紧集上的连续函数。最后通过一个复杂非线性系统的仿真,验证了本文方法的有效性。 相似文献