基于T—S模糊模型的多变量预测控制

提出一种基于T-S模糊模型的多输入多输出预测控制策略.T-S模糊模型用于描述对象的非线性动态特性,模糊规则将非线性系统划分为多个局部子线性模型.为提高预测控制性能,采用多步线性化模型构成多步预报器,从而将预测控制中的非线性优化问题转化为一个线性二次寻优问题.串接贮槽液位控制系统的仿真结果表明,多步线性化模型预测控制性能优于单步线性化模型预测控制性能.     

一种基于T-S模型的模糊预测控制

提出了一种基于T-S模型的模糊预测控制策略。T-S模糊模型用来描述对象的非线性动态特性,通过当前的工况参数实时在线的修正每一时刻的阶跃响应模型参数,将模糊模型作为常规线性预测控制DMC方法的预测模型,从而把T-S模型对复杂的非线性系统的良好描述特性和预测控制的滚动优化算法相结合,来实现利用常规线性预测控制策略对非线性系统的有效控制,有效地解决了复杂工业过程的强非线性问题。pH中和过程的仿真结果表明其性能明显优于传统的PID控制器。     

模糊预测控制炉窑温度系统中应用

针对炉窑温度系统的大时滞、多扰动和非线性的特点,将T-S模糊状态空间模型作为预测控制的预测模型,并将T-S模糊表示的非线性系统转化为线性时变系统,给出了基于状态空间的多变量复杂系统的T-S模糊模型表达形式,设计出预测时域内多模型的非线性模糊预测控制器。根据实际控制中对控制量和输出的约束,将控制器输出求解转化为二次规划问题。     

基于T-S模型的Chua混沌系统模糊变结构控制

针对Chua混沌系统这一复杂的非线性系统给出一种基于T-S模型的模糊变结构控制律设计。首先采用T-S模糊动态模型描述非线性系统,得到混沌系统的全局模糊模型;然后采用Lyapunov稳定性理论设计出确保模糊动态模型全局渐近稳定的变结构控制器,将模糊控制与成熟的线性变结构控制相结合,来解决非线性系统控制问题。仿真验证了方案的有效性。模糊控制器简单,规则少。     

使用鲁棒控制器稳定模糊系统模型

将非线性系统用T-S模糊动态模型描述,并将全局模糊系统模型表示成不确定系统形式采用新的鲁棒控制器设计方法,设计出使全局模糊系统模型渐近稳定的线性控制器避免了并行分配补偿法中求解公共矩阵P的困难.一级倒立摆的模糊控制器设计实例,证明了方案的简洁有效.     

T-S模糊算法在水箱液位非线性控制中的应用

通过实验手段及机理建模法获得多容水箱液位控制的分段线性化数学模型,从而采用T-S型模糊算法构成控制器,不仅能在每个模糊子区间中建立分段线性模型,还能借助隶属度函数将各分段线性模型平稳地连接成一个整体非线性系统模型,有效克服参数突变而引起的扰动,进一步提高控制系统动态响应性能。     

多变量非线性系统的模糊内模控制

大多数的先进控制器是基于线性模型的,它们对化学工业中常见的非线性过程的控制效果并不能达到最优.因此,考虑使用非线性模型,以使控制性能获得改善.用基于T-S模型的自适应模糊聚类辨识算法对系统进行辨识.T-S模型是用线性的方程来描述非线性系统,从而利于求出模型的逆.而模型逆又是IMC的关键一步,因此选用这种基于T-S模糊模型的控制器(FIMC)来实现对非线性多变量系统的控制.对2输入2输出的非线性系统进行仿真,结果表明FIMC在多变量系统中可以实现好的控制.     

基于T-S模型的非线性系统的最终滑动模态控制

采用T_S模糊动态模型逼近非线性系统, 将非线性系统模糊化为局部线性模型. 用Lyapunov稳定性理论设计出确保T-S模型全局渐近稳定的变结构控制器. 采用单位向量控制形式的最终滑动模态控制器, 对满足匹配条件和不满足匹配条件的不确定性均适用. 以倒立摆为模型的仿真实验, 验证了方案的有效性.     

非线性时延网络控制系统的模糊建模与控制

针对时变网络诱导时延小于一个采样周期的非线性时延网络控制系统,讨论系统的稳定性及控制器的设计方法.利用基于“IF-THEN”规则的模糊模型近似系统中的非线性,将时延的不确定性转化为系统参数的不确定性,从而将此类非线性网络控制系统建模为一类具有参数不确定性的离散Takagi-Sugeno（T-S）模糊模型.基于建立的模型,利用Lyapunov方法和线性矩阵不等式方法,分析了系统的稳定性及模糊状态反馈控制器的设计方法,最后通过仿真实例验证了所提出方法的有效性.     

T-S模糊系统的有限时间控制

面向具有强非线性的复杂工业过程,利用T-S模糊模型逼近原非线性系统,把T-S模糊模型逼近非线性系统存在的误差描述成有界时变的扰动,进而提出带扰动的T-S模糊系统的有限时间控制方法.首先,给出线性系统有限时间有界性的一个充分条件,与现有结果相比,该条件具有较小的保守性,并可以处理扰动是时变的情况;然后,提出T-S模糊系统有限时间镇定控制器的设计方法;最后,给出基于线性矩阵不等式(LMI)的控制器设计算法,并通过数值算倒演示所给方法的有效性.     

Enlarging the terminal region of quasi-infinite horizon NMPC based on T-S fuzzy model

The paper presents a method for enlarging the terminal region of quasi-infinity horizon nonlinear model predictive control (NMPC) for nonlinear systems with constraints. The main technique builds on the fact that terminal controllers are fictitious and never applied to the system in the quasi-infinite horizon NMPC [1]. Based on T-S fuzzy models of nonlinear systems, we show that a parameter-dependent state feedback law exists such that the corresponding value function and its level set can be served as terminal cost and terminal region. The problem of maximizing the terminal region is formulated as a convex optimization problem based on linear matrix inequalities (LMIs). A numerical example is given to illustrate the effectiveness of the proposed method.     

一种基于T-S模糊模型的混沌控制方法

用T-S模糊系统来逼近非线性系统,它的IF-THEN规则后件由线性状态空间子系统构成,进而可以应用模糊系统的控制理论求得模糊控制器,用此非线性控制器来控制非线性系统,以求良好的控制效果;将模糊控制技术应用于混沌控制中,可以克服反馈线性化等传统方法对参数完全精确已知的限制;模糊规则后件部分以局部线性方程形式给出的T-S模糊模型可以通过调整相关参数很好地逼近混沌系统,基于该模型采用平行分散补偿技术设计出具有相同规则数目的模糊控制器,控制器所有参数可以通过求解一组线性矩阵不等式一次性得到。仿真结果验证了该方法的有效性。     

Variable-Gain Controllers for Nonlinear Systems Using the T–S Fuzzy Model

This correspondence proposes two novel control schemes with variable state-feedback gain to stabilize a Takagi-Sugeno (T-S) fuzzy system. The T-S fuzzy model is expressed as a linear plant with nonlinear disturbance terms in both schemes. In controller I, the T-S fuzzy model is expressed as a linear plant around a nominal plant arbitrarily selected from the set of linear subsystems that the T-S fuzzy model consists of. The variable gain then becomes a function of a gain parameter that is computed to neutralize the effect of disturbance term, which is, in essence, the deviation of the actual system dynamics from the nominal plant as the system traverses a specific trajectory. This controller is shown to stabilize the T-S fuzzy model. In controller II, individual linear subsystems are locally stabilized. Fuzzy blending of individual control actions is shown to make the T-S fuzzy system Lyapunov stable. Although applicability of both control schemes depends on the norm bound of unmatched state disturbance, this constraint is relaxed further in controller II. The efficacy of controllers I and II has been tested on two nonlinear systems     

一类非线性系统的模糊变结构控制

研究了一类非线性系统的模糊变结构控制问题，并给出了稳定性证明。通过将非线性系统化为多个精确T—S模型来建立非线性系统精确的T—S模糊模型，将模糊理论与成熟的线性变结构控制理论相结合设计一种模糊变结构控制器，用Lyapunov稳定性理论证明该控制器能确保模糊动态模型全局渐近稳定，从而使非线性系统稳定。仿真结果表明了该设计方法的有效性。     

Variable-gain controllers for nonlinear systems using the T-S fuzzy model.

This correspondence proposes two novel control schemes with variable state-feedback gain to stabilize a Takagi-Sugeno (T-S) fuzzy system. The T-S fuzzy model is expressed as a linear plant with nonlinear disturbance terms in both schemes. In controller I, the T-S fuzzy model is expressed as a linear plant around a nominal plant arbitrarily selected from the set of linear subsystems that the T-S fuzzy model consists of. The variable gain then becomes a function of a gain parameter that is computed to neutralize the effect of disturbance term, which is, in essence, the deviation of the actual system dynamics from the nominal plant as the system traverses a specific trajectory. This controller is shown to stabilize the T-S fuzzy model. In controller II, individual linear subsystems are locally stabilized. Fuzzy blending of individual control actions is shown to make the T-S fuzzy system Lyapunov stable. Although applicability of both control schemes depends on the norm bound of unmatched state disturbance, this constraint is relaxed further in controller II. The efficacy of controllers I and II has been tested on two nonlinear systems.     

MIMO系统的多模型预测控制

针对非线性多变量系统提出一种多模型预测控制(MMPC)策略.首先给出一种多模型 辨识方法,利用模糊满意聚类算法将复杂非线性系统划分为若干子系统,并获得多个线性模型, 通过模型变换得出全局系统模型,接着对全局MIMO系统设计MMPC,并进行了系统的性能分 析,最后以pH中和过程为例,通过仿真研究验证了辨识和控制算法的有效性.     

Fuzzy State-Space Modeling and Robust Observer-Based Control Design for Nonlinear Partial Differential Systems

In this paper, a robust fuzzy control design is proposed for the stabilization of nonlinear partial differential systems (NPDSs). Based on Galerkin's method, a Takagi-Sugeno (T-S) fuzzy PDS is first proposed to model an NPDS. Then, the T-S fuzzy PDS can be represented by a finite-dimensional T-S fuzzy subsystem in controlled mode and a coupled infinite-dimensional T-S fuzzy subsystem in residual mode. Therefore, the NPDS can be partitioned into a finite-dimensional T-S fuzzy slow state-space subsystem to be controlled and a coupled infinite-dimensional fast residual subsystem to be tolerated. Based on the small-gain theorem, a robust fuzzy observer-based controller is developed to tolerate the coupled residual subsystem to asymptotically stabilize the NPDS. Furthermore, based on the dissipative theory, an Hinfin control design is proposed to attenuate the effects of external disturbances and measurement noises on the robust stabilization of NPDSs. The MATLAB linear matrix inequality toolbox can be employed to efficiently solve the optimal Hinfin fuzzy observer-based control design problem of NPDSs. Finally, a simulation example is given to illustrate the design procedure and confirm the performance of the proposed robust fuzzy observer-based control method for the perturbative NPDSs.     

Design of observer based nonlinear model predictive controller for a continuous stirred tank reactor

Model predictive control (MPC) schemes are now widely used in process industries for the control of key unit operations. Linear model predictive control (LMPC) schemes which make use of linear dynamic model for prediction, limit their applicability to a narrow range of operation (or) to systems which exhibit mildly nonlinear dynamics.

In this paper, a nonlinear observer based model predictive controller (NMPC) for nonlinear system has been proposed. An approach to design NMPC based on fuzzy Kalman filter (FKF) and augmented state fuzzy Kalman filter (ASFKF) has been presented. The efficacy of the proposed NMPC schemes have been demonstrated by conducting simulation studies on the continuous stirred tank reactor (CSTR). The analysis of the extensive dynamic simulation studies revealed that, the NMPC schemes formulated produces satisfactory performance for both servo and regulatory problems. Simulation results also include an inferential control case, where the reactor concentration is not measured but estimated from temperature measurement and used in the NMPC based on FKF and ASFKF formulations.     

基于模糊T-S模型的批过程建模与最优控制

基于模糊T-S模型,提出一种具有自学习能力的模糊方法用于批过程建模和最优控制.通过引入与均方误差相关的动态误差传递因子,使用改进的梯度下降法,本方法能够辨识模糊T-S预测模型.对于批过程的受限非线性最优控制,基于所辨识的预测模型,运用庞特里亚金最小值原理和平行分布补偿算法,本方法能够把一个复杂非线性系统最优控制设计问题转化为一些基于复杂T-S预测模型的局部线性系统的最优问题,从而给出一种有效和简单的模糊最优控制策略.所提方法用于一个半连续式反应器的建模和最优控制,仿真结果表明新方法是有效和准确的.