量子进化算法研究进展

在介绍量子进化算法(QEA)的原理、特点和基本流程的基础上,重点综述QEA的改进,包括改进基本算子、引入新算子、改变种群规模、扩展为并行算法和构造新型算法框架等.介绍了QEA的应用研究,进而提出了QEA在理论、算法、组合优化、多目标优化与约束优化、不确定优化及应用方面的若干进一步的研究内容.     

一种工业过程稳态优化控制算法

针对带有输出关联约束的工业过程,提出一种确定其稳态优化控制的算法.首先通过对数变换将原问题转化为一个等价而且可在对数空间求解的优化控制问题;然后为避免事先选择一个合适罚系数的困难,在算法中引入了目标函数的线性化形式.该优化算法不仅能收敛到正确的系统最优解,而且可用现有的二次规划算法计算.应用简单的滤波技术,改善了算法在有量测噪声情况下的性能.仿真结果表明,所提出的优化算法是有效的.     

一种辨识Wiener-Hammerstein模型的新方法

针对非线性Wiener-Hammerstein模型,提出利用粒子群优化算法对非线性模型进行辨识的新方法.该方法的基本思想是将非线性系统的辨识问题转化为参数空间上的优化问题;然后采用粒子群优化算法获得该优化问题的解.为了进一步增强粒子群优化算法的辨识性能,提出利用一种混合粒子群优化算法.最后,仿真结果验证了该方法的有效性和可行性.

     

垂直分布多决策表下基于条件信息熵的近似约简

目前粗糙集理论研究主要针对单个决策表,而有关分布式环境下的核求解和属性约简研究的报道不多,为此提出垂直分布多决策表下基于条件信息熵的近似约简算法.该算法在各局部站点并行求相应的条件信息熵,并通过传送部分等价类的策略,可有效降低通讯代价,提高垂直分布多决策表下基于条件信息熵的近似约简效率 .算法分析和实验结果表明,所提出的算法是有效可行的.

     

连续不确定模糊系统的静态输出反馈控制

对于一类状态矩阵、输入矩阵和扰动输入矩阵中均含有不确定项的连续T-S模糊系统,研究其静态输出反馈控制问题.用矩阵不等式的形式给出了该模糊系统可通过静态输出反馈控制稳定的充分条件,并将矩阵不等式的条件转化为迭代线性矩阵不等式,同时给出了相应的迭代算法.最后用数值仿真例子说明了该算法的有效性和收敛性.     

群集系统的软控制

考虑欧氏空间中群集动态系统的“软控制”问题,即在不改变群集系统中个体间现有规则的条件下,通过增加一个或多个可控智能体干扰群集个体的行为,使群集中心转移到期望的位置.给出了可控智能体的控制规则,并利用粒子群(PSO)算法讨论了群集系统软控制的最优收敛问题.实例研究表明了“软控制”在群集系统中的可行性.

     

基于观测器的飞行器时变控制效益估计算法

研究飞行器时变控制效益的在线估计方法,证明了系统控制效益可估计的充分条件. 针对效益矩阵分段连续时变的情形,给出了基于观测器,方程求解和最小二乘法的在线估计方法,分析和证明了算法的收敛性。 数值仿真结果表明,该算法能快速估计时变控制效益,具有良好的稳定性和鲁棒性。

     

一种核属性快速求解算法

针对求核算法存在所求得的核与基于正区域的核不一致以及算法的时间和空间复杂度不理想的问题,提出一种新的求核方法,并证明了由该方法所获得的核与基于正区域的核是一致的.利用分布计数基数排序方法设计了一种高效的等价类求解算法,在此基础上给出了快速求核算法.实验表明,所提出的算法是正确而高效的.

     

文本聚类集成问题中的谱算法

聚类集成中的关键问题是如何根据不同的聚类成员组合为更好的聚类结果．引入谱聚类算法解决该问题,提出了基于相似度矩阵的谱算法（ＳＭＳＡ）,但该算法高昂的计算代价使其不适合大规模文本集．进一步研究了谱聚类算法的特性,对超边的相似度矩阵进行谱分析,提出了基于超边相似度矩阵的元聚类算法（ＨＳＭ-ＭＣＬＡ）．真实文本数据集的实验结果表明：ＳＭＳＡ 和ＨＳＭ-ＭＣＬＡ 比其他基于图划分的集成算法更优越;ＨＳＭ-ＭＣＬＡ 可获得与ＳＭＳＡ 相当的结果,而计算需求却明显低于ＳＭＳＡ．

     

力矩受限的机器人吸引域估计方法

针对力矩受限的机器人组合非线性反馈控制的局部稳定区域描述问题,研究了吸引域的估计方法.利用不变集属性和椭球性质,定义两种不同意义的最大椭球不变集来逼近吸引域,分别采用设置初始状态法和参考形状集法求解.通过带有约束的优化问题描述,所有条件均能转化为线性矩阵不等式条件,易于求解.由于采用优化技术,能够减小吸引域估计的保守性.数值算例验证了所提方法的有效性.

     

基于关联矩阵代数运算的逻辑型监控器设计

对于含有不可控变迁的Petri网监控问题,允许状态空间可能需要一组“或”的允许约束来描述,而库所不变量的监控方法[12]只将给定约束转换为单个的允许约束,其监控器将系统行为限制在允许标识状态空间的较小子集内,其限制性过于严格,且该方法无法解决某些监控问题.针对上述问题,给出了一种基于关联矩阵代数运算的约束转换方法,能够...     

线性参数不确定系统的H-鲁棒控制器设计

本文主要讨论了带有未知不确定参数的线性系统的H_∞鲁棒控制问题,这里假定其中的不确定性是时变有界的,并同时存在于系统的状态矩阵和输入矩阵中,文中提出了一种同时使受控对象保持二次稳定并满足干扰约束的状态反馈设计方法。结果表明,该类反馈控制律可以通过求解一个含有参数的代数Riccati方程得到。     

A finite element method for plane strain deformations of incompressible solids

A finite element method for incompressible deformation is formulated from the virtual work equation based on deviatoric quantities. Particular emphasis is given to nonlinear material behavior. The incompressibility constraint is imposed on the admissible displacement field by direct elimination of nodal displacements. The resulting stiffness matrix is symmetric and positive definite. Once a convergent solution for the displacement is obtained, the hydrostatic stress is determined from the principle of virtual work. A variety of illustrative examples are presented. The efficiency, economy and limitations of the method are discussed.     

Scheduled control for robust attenuation of non-stationary sinusoidal disturbances with measurable frequencies

Attenuation of sinusoidal disturbances with uncertain yet online measurable frequencies is considered. The disturbances are modeled as the outputs of an undisturbed parameter-dependent exogenous system with a skew-symmetric system matrix, obtained in response to nonzero initial conditions. The problem is formulated for a parameter-dependent plant as the synthesis of a parameter-dependent controller in a way to ensure internal stability as well as a desired level of steady-state disturbance attenuation in the face of all admissible parameter variations. The solvability of this problem is first related to the existence of bounded solutions to a matrix differential regulator equation subject to an asymptotic norm constraint. Reformulating this as a parameter-dependent state-feedback like synthesis, based on which suitable solutions to the differential regulator equation can be obtained online, tractable solvability conditions are then provided in the form of parameter-dependent matrix inequalities. Controllers that solve the generalized asymptotic regulation problem are also parameterized in terms of the suitable solutions of the differential regulator equation and some free parameter-dependent matrices that are to be designed off-line to ensure stability. A procedure is then developed to design the free parameters in a way to achieve desirable transient behavior. The use of the developed synthesis procedure is illustrated on a simplified version of the course control problem in ship steering.     

满意滤波在航迹辨识中的应用

利用线性矩阵不等式(LMI,linear matrix inequalities)方法,首先研究了Kalman滤波的稳态误差方差和滤波增益的解法,并根据满意控制的思想,提出了具有误差方差上界约束的滤波问题,然后研究了误差方差上界约束下对系统测量噪声具有最大容许强度的满意鲁棒滤波.本文的研究成果已被应用于某型C3I系统中的航迹辨识.     

ROBUST Hinfinity CONTROL FOR SYSTEMS WITH TIME-VARYING PARAMETER UNCERTAINTY AND VARIANCE CONSTRAINTS

In this paper, the problem of designing robust Hinfinity controllers for linear continuous-time systems subjected to time-varying parameter uncertainty and steady-state variance constraints is considered. The goal of this problem is to design the state feedback controller, such that for all admissible time-varying parameter perturbations, the steady-state variance of each state is not more than the individual prespecified upper bound and the Hinfinity norm of the transfer function from disturbance inputs to system outputs meets the prespecified upper bound constraint, simultaneously. The parameter uncertainties are allowed to be time-varying and norm-bounded. A purely algebraic matrix equation approach is effectively utilized to solve the problem addressed. The existence conditions as well as the explicit expression of desired controllers are presented, and two illustrative examples are used to demonstrate the applicability of the proposed design procedure.     

Maximally permissive supervisor synthesis based on a new constraint transformation method

The method is proposed to design the maximally permissive and efficient supervisor for enforcing linear constraints, in which the weights of places are not negative, on ordinary Petri nets with uncontrollable transitions. First, the weakly admissible linear constraint is introduced. Second, a method is proposed to design the monitor place for enforcing a weakly admissible linear constraint on Petri nets. Third, a theorem proving that a linear constraint can be equivalently transformed at an uncontrollable transition into a disjunction of new constraints is proposed. Fourth, using this theorem, an algorithm is presented to equivalently transform a linear constraint, each place weight of which is not negative, into a disjunction of weakly admissible ones. Lastly, the supervisor, which consists of the plant net and a set of monitor places, is designed for the weakly admissible linear constraints calculated by the above algorithm.     

A new approach on designing l1 optimal regulator with minimum order for SISO linear systems

For a SISO linear discrete-time system with a specified input signal, a novel method to realize optimal l1 regulation control is presented. Utilizing the technique of converting a polynomial equation to its corresponding matrix equation, a linear programming problem to get an optimal l1 norm of the system output error map is developed which includes the first term and the last term of the map sequence in the objective function and the right vector of its constraint matrix equation, respectively. The adjustability for the width of the constraint matrix makes the trade-off between the order of the optimal regulator and the value of the minimum objective norm become possible, especially for achieving the optimal regulator with minimum order. By norm scaling rules for the constraint matrix equation, the optimal solution can be scaled directly or be obtained by solving a linear programming problem with l\ norm objective.     

A new approach on designing l_1 optimal regulator with minimum order for SISO linear systems

For a SISO linear discrete-time system with a specified input signal, a novel method to realize optimal l1 regulation control is presented. Utilizing the technique of converting a polynomial equation to its corresponding matrix equation, a linear programming problem to get an optimal l1 norm of the system output error map is developed which includes the first term and the last term of the map sequence in the objective function and the right vector of its constraint matrix equation, respectively. The adjustability for the width of the constraint matrix makes the trade-off between the order of the optimal regulator and the value of the minimum objective norm become possible, especially for achieving the optimal regulator with minimum order. By norm scaling rules for the constraint matrix equation, the optimal solution can be scaled directly or be obtained by solving a linear programming problem with l\ norm objective.     

Synthesis of minimax optimal controllers for uncertain time-delay systems with structured uncertainty

This paper is concerned with the design of robust state feedback controllers for a class of uncertain time-delay systems. The uncertainty is assumed to satisfy a certain integral quadratic constraint. The controller proposed is a minimax optimal controller in the sense that it minimizes the maximum value of a corresponding linear quadratic cost function over all admissible uncertainties. The controller leads to an absolutely stable closed loop uncertain system and is constructed by solving a finite dimensional parameter-dependent algebraic Riccati equation.