基于拉盖尔神经网络的多输入非线性系统建模研究

１引言在神经网络的研究中,新的有效模型的构造是一个极为重要的方面,但至今仍没有共同认可的构造方法或准则,往往依赖于具体对象,凭借经验或试验的方法选取神经网络模型,这就难以保证所构造的神经网络性能最优。另外,基于Ｓ型函数的ＢＰ网络学习时间长,一直是个难...     

输入死区下的多输入多输出系统自适应神经网络容错控制

针对一类具有传感器故障和不对称输入死区的非线性多输入多输出非严格反馈系统,本文提出一种自适应神经网络容错控制方案.控制器的设计以反步法为框架,采用自适应神经网络控制方法处理传感器故障,利用死区斜率的有界性补偿输入死区对系统性能造成的影响,同时引入动态面控制技术克服“计算爆炸”的问题.该控制方法不仅能够保证闭环系统中所有...     

多输入非线性串级系统的非过参数化自适应控制

证明了一大类含有未知参数的多输入非线性串级系统在适当的假设条件下是可全局适应稳定的,自适应控制律的设计是基于ｂａｃｋｓｔｅｐｐｉｎｇ递推设计方法,得到的参数自适应律的阶次等于未知参数的个数,因此该设计是非过参数化的。     

基于输入输出线性化方法的一类多输入多输出非线性系统的观测器设计

研究一类多输入多输出仿射非线性系统的状态观测器设计问题. 基于输入输出线性化方法提出了一类多输入多输出仿射非线性系统的状态观测器设计的新方法, 并给出保证状态估计误差渐近趋于零的充分条件. 算例表明了所得结果的有效性.     

多输入非线性数学模型的研究

以往使用的典型非线性数学模型为单变量模型，其存在着较大的局限性，如间隙非线性模型。本文提出了一种多输入的间隙非线性模型，它能较好地实现过去流行的单变量间隙模型无法进行的数字仿真。     

一类上三角随机非线性系统的状态反馈镇定

针对一类具有上三角结构的随机非线性系统,研究其状态反馈镇定问题.通过引入有效的坐标变换,将所要研究的系统转化为一个具有可调增益的等价系统;然后利用低增益齐次占优技术,通过巧妙地选取低增益参数,使得整个闭环系统达到依概率全局渐近稳定.主要贡献是,将低增益齐次占优技术推广到了随机系统,并解决了一类上三角随机系统的镇定问题.数值仿真验证了所提出控制方案的有效性.     

多输入多输出系统的数据分层建模

为了高效准确地实现多输入多输出系统的数据建模,本文提出了数据分层建模算法.将多输入多输出数据建模问题分解为一系列单输入多输出的建模问题,同时改进标准遗传编程算法,将单树表示的的个体结构扩展为向量树的进化个体,实现多输出系统的自动建模.通过大量的计算实例表明,这种算法可以实现复杂的多输入多输出系统的建模,提高数据建模的效率和精度.     

Geometric characterization of multi-input lower-triangular forms

This paper is concerned with the problem as to whether a multi-input nonlinear system is equivalent to the so-called low-triangular form.Two elemental forms of multi-input lower-triangular systems are proposed.Then,using the theory of singular distributions,the necessary and sufficient conditions under which multi-input nonlinear systems are locally feedback equivalent to these two lower-triangular systems are established.Furthermore,algorithms are provided to describe how to realize these equivalent transf...     

一类上三角随机非线性系统的输出反馈控制

针对一类上三角随机非线性系统的输出反馈控制问题,首先利用反推技术,为其对应的标称系统设计稳定的输出反馈控制器;然后利用低增益齐次占优技术,为整个系统设计输出反馈控制器.所设计的控制器能保证闭环系统的平衡点为依概率全局渐近稳定的,并将低增益齐次占优技术推广到了随机系统,首次解决了一类上三角随机系统的镇定问题.最后通过数值仿真验证了所提出控制方案的有效性.     

多输入的二阶广义分布参数系统的控制综合问题

广义分布参数系统具有广泛的实际背景.如复合材料中的温度分布,电缆中的信号传播,电磁耦合超导线路中的电压分布,飞行器姿态控制等问题研究中都会出现这样的系统.极点配置与反馈稳定性是这类系统研究的重要方面.本文应用泛函分析及算子理论讨论了Hilbert空间中多输入的二阶广义分布参数系统的极点配置与反馈稳定性问题,获得了这类系统极点可配置与可镇定的一些充分条件,并利用复分析、复级数、有界线性算子的广义逆等方法建立了反馈控制律的构造性表达式.本文结论不仅具有重要的实际意义,而且对广义分布参数系统的控制综合问题研究具有重要的理论价值.     

Robust control design of a class of nonlinear systems in polynomial lower-triangular form

This paper investigates the problem of global robust stabilization for a wide class of nonlinear systems, called polynomial lower-triangular form (pLTF), which expands LTF to a more general case. The aim is explicitly constructing the smooth controller for the class of systems with static uncertainties, by adding and modifying a power integrator in a recursive manner. The pLTF relaxes the restrictions on the structure of the normal LTF and enlarges the family of systems that are stabilizable. Examples are also provided to show the practical usage of this class of systems and the effectiveness of the design method. Recommended by Editorial Board member Hyungbo Shim under the direction of Editor Jae Weon Choi. Bing Wang received the B.S. degree from the Huazhong University of Science and Technology, and the Ph.D. degree from the University of Science and Technology of China, in 1998 and 2006, respectively. He is currently working in College of Electrical Engineering, Hohai University. His research interests include robust control, nonlinear control and power systems. Haibo Ji received the B.S. and Ph.D. degrees in Mechanical Engineering from ZheJiang University and Beijing University in 1984 and 1990 respectively. He is currently a Professor in the Dept. of Automation, USTC. His research interests include nonlinear control and adaptive control. Jin Zhu received the B.S. and Ph.D. degrees in Control Science and Engineering from University of Science & Technology of Chinain 2001 and 2006 respectively. He is currently a Post-doc in Han-Yang University, Korea. His research interests include Markovian jump systems and nonlinear control.     

Pole assignment for multi-input multi-output systems using output feedback

In this paper the problem of pole assignment using constant gain output feedback is studied for MIMO system with system order n > m + l − 1, where m and l are the number of inputs and outputs, respectively. A new procedure is presented to design a constant gain output feedback matrix which assigns (m + l − 2) poles exactly to the desired locations and shifts all the unassigned poles to suitable locations using root locus techniques.     

Nonlinear disturbance observer-based control for multi-input multi-output nonlinear systems subject to mismatching condition

For a multi-input multi-output (MIMO) nonlinear system, the existing disturbance observer-based control (DOBC) only provides solutions to those whose disturbance relative degree (DRD) is higher than or equal to its input relative degree. By designing a novel disturbance compensation gain matrix, a generalised nonlinear DOBC method is proposed in this article to solve the disturbance attenuation problem of the MIMO nonlinear system with arbitrary DRD. It is shown that the disturbances are able to be removed from the output channels by the proposed method with appropriately chosen control parameters. The property of nominal performance recovery, which is the major merit of the DOBCs, is retained with the proposed method. The feasibility and effectiveness of the proposed method are demonstrated by simulation studies of both the numerical and application examples.     

Finite spectrum assignment of multi-input systems with non-commensurate delays

We present a new framework for finite spectrum assignment for multi-input systems with non-commensurate delays using an algebraic approach over multidimensional polynomial matrices. By focusing on the solvability of a Bezout equation over multidimensional polynomial matrices, we derive a necessary and sufficient condition for finite spectrum assignability under which a finite number of spectra can be assigned by a control law using a ring of entire functions, i.e. Laplace transforms of all exponential time functions with compact support. Furthermore, using a solution to the Bezout equation, we present a design method for a controller that achieves finite spectrum assignment.     

一种多输入单输出Hammerstein系统的集成辨识方法

针对多输入单输出(MISO)Hammerstein系统提出了一种稳态与动态辨识相结合的集成辨识方法.该方法利用稳态信息获取稳态模型的强一致性估计,并通过稳态模型以神经网络获得其非线性逼近函数,再利用动态信息辨识获取多输入单输出(MISO)Hammerstein系统的线性子系统未知参数的一致性估计.仿真结果表明了该方法的有效性和实用性.     

ℒ1 adaptive controller for a class of non-affine multi-input multi-output nonlinear systems

In this article, an extension of the ?₁ adaptive control design is introduced for a class of non-affine Multi-Input Multi-Output nonlinear systems with unknown dynamics and unmeasured states. The system dynamics is represented in the normal form with the bounded-input-bounded-output internal dynamics. At first, a stable virtual reference counterpart is constructed. Thereafter, a piece-wise continuous adaptive law is introduced to the actual system along with a low-pass filtered control signal that allows for achieving arbitrarily close tracking of the input and the output signals of the reference system. Rigorous mathematical proof is provided, and the theoretical results are verified with the simulation.     

互联多输入系统的分散自适应L2增益控制

为了实现一类非下三角结构互联多输入系统的鲁棒控制,提出一种基于状态量测的非线性自适应L2增益分散干扰抑制方法,并给出了规律性计算公式,克服了反复递推设计的不足,通过控制律中引入K类函数,提高了状态变量的收敛速度.该方法应用到了多机广域电力系统分散励磁控制中,仿真结果表明:在大扰动情况下,相对于传统L2增益抑制方法,新方法能够有效抑制外部干扰,提高各状态变量的响应速度,对于增强电力系统的暂态稳定性具有重要意义.     

非线性系统结构的伪分解及反馈等价

本文主要讨论了非线性系统一种被称为伪分解的特殊结构分解问题，给出了伪分解的充分条件以及分解后得到的系统反馈性化的充要条件。     

Set-point-related indirect iterative learning control for multi-input multi-output systems

A form of iterative learning control (ILC) is used to update the set-point for the local controller. It is referred to as set-point-related (SPR) indirect ILC. SPR indirect ILC has shown excellent performance: as a supervision module for the local controller, ILC can improve the tracking performance of the closed-loop system along the batch direction. In this study, an ILC-based P-type controller is proposed for multi-input multi-output (MIMO) linear batch processes, where a P-type controller is used to design the control signal directly and an ILC module is used to update the set-point for the P-type controller. Under the proposed ILC-based P-type controller, the closed-loop system can be transformed to a 2-dimensional (2D) Roesser s system. Based on the 2D system framework, a sufficient condition for asymptotic stability of the closed-loop system is derived in this paper. In terms of the average tracking error (ATE), the closed-loop control performance under the proposed algorithm can be improved from batch to batch, even though there are repetitive disturbances. A numerical example is used to validate the proposed results.