Adaptive infinite impulse response system identification using opposition based hybrid coral reefs optimization algorithm

An efficient global adaptive algorithm is required to determine the parameters of infinite impulse response (IIR) filter owing to the error cost surface of adaptive IIR system identification problem being generally nonlinear and non-differentiable. In this paper, a new bio-inspired algorithm, called opposition based hybrid coral reefs optimization algorithm (OHCRO) is applied for the IIR system identification problem. Coral reefs optimization algorithm (CRO) is a novel global algorithm, which mimics the behaviors of corals’ reproduction and coral reef formation. OHCRO is a modified version of CRO, on the one hand utilizing opposition based learning to accelerate global convergence, on the other hand cooperating with rotational direction method to enhance the local search capability. In addition, the Laplace broadcast spawning and power mutation brooding operator are used to maintain the diversity. The simulation studies have been performed for the performance comparison of genetic algorithm, particle swarm optimization and its variants, differential evolution and its variants and the proposed OHCRO for well-known benchmark examples with same order and reduced order filters. Simulation results and comparative studies justify the efficacy of the OHCRO based system identification approach in terms of convergence speed, identified coefficients and fitness values. In conclusion, OHCRO is a promising method for adaptive IIR system identification.     

High order stable infinite impulse response filter design using cuckoo search algorithm

In this paper, an efficient technique for optimal design of digital infinite impulse response (IIR) filter with minimum passband error (e _p ), minimum stopband error (e _s ), high stopband attenuation (A _s ), and also free from limit cycle effect is proposed using cuckoo search (CS) algorithm. In the proposed method, error function, which is multi-model and non-differentiable in the heuristic surface, is constructed as the mean squared difference between the designed and desired response in frequency domain, and is optimized using CS algorithm. Computational efficiency of the proposed technique for exploration in search space is examined, and during exploration, stability of filter is maintained by considering lattice representation of the denominator polynomials, which requires less computational complexity as well as it improves the exploration ability in search space for designing higher filter taps. A comparative study of the proposed method with other algorithms is made, and the obtained results show that 90% reduction in errors is achieved using the proposed method. However, computational complexity in term of CPU time is increased as compared to other existing algorithms.     

Mechatronic systems identification using an impulse response recursive algorithm

A recursive identification algorithm is used to identify mechatronic systems using impulse response data. The algorithm is based on an auto regressive moving average (ARMA) model with a steepest descent method to minimize the least square error between the original and predicted outputs. Two mechatronic systems are tested: DC motor and gyroscope. Impulse voltage input is used to excite the system and the angular speed output is measured. In both systems, the torque and angular velocity outputs are dependent on the voltage and current inputs. This relationship is governed by characteristics such as inductance, resistance, moment of inertia, friction, load, and system constants. Once the ARMA model is constructed, the transfer function is realized. Then the input voltage is varied and the identified model results are compared with the original system. Simulation results using Simulink and experimental results using Labview with data acquisition card (DAQ) are presented. Results show that the recursive identification algorithm is able to identify the two systems with minimal error.     

Harmony search algorithm for image reconstruction from projections

Image reconstruction from projections is an important problem in the areas of microscopy, geophysics, astrophysics, satellite and medical imaging. The problem of image reconstruction from projections is considered as an optimization problem where a meta-heuristic technique can be used to solve it. In this paper, we propose a new method based on harmony search (HS) meta-heuristic for image reconstruction from projections. The HS method is combined then with a local search method (LS) to improve the quality of reconstructed images in tomography. The two proposed methods (HS and hybrid HS) are validated on some images and compared with both the filtered back-projection (FBP) and the simultaneous iterative reconstruction technique (SIRT) methods. The numerical results are encouraging and demonstrate the benefits of the proposed methods for image reconstruction in tomography.     

配送中心选址问题的和谐搜索算法

针对一类配送中心选址问题,建立了问题的数学模型,将和谐搜索算法进行改进并对问题进行求解,最后将此算法与最优保存算法(EGA)和遗传算法(GA)进行比较,验证了算法在计算结果方面的精确性和计算时间上的高效性。     

On optimal infinite impulse response edge detection filters

The authors outline the design of an optimal, computationally efficient, infinite impulse response edge detection filter. The optimal filter is computed based on Canny's high signal to noise ratio, good localization criteria, and a criterion on the spurious response of the filter to noise. An expression for the width of the filter, which is appropriate for infinite-length filters, is incorporated directly in the expression for spurious responses. The three criteria are maximized using the variational method and nonlinear constrained optimization. The optimal filter parameters are tabulated for various values of the filter performance criteria. A complete methodology for implementing the optimal filter using approximating recursive digital filtering is presented. The approximating recursive digital filter is separable into two linear filters, operating in two orthogonal directions. The implementation is very simple and computationally efficient. has a constant time of execution for different sizes of the operator, and is readily amenable to real-time hardware implementation     

基于结构进化的无限冲激响应数字滤波器设计方法

针对传统无限脉冲响应(IIR)数字滤波器设计方法存在传输函数在整个设计阶段可能不是最优的问题,提出一种基于遗传算法结构进化的IIR数字滤波器生成方法.该方法直接设计滤波器结构,无需设计传输函数.首先,随机建立一组滤波器结构生成指令序列(SGIS).这些指令序列不仅能控制滤波器结构,也能表示滤波器结构.然后,对这些指令序列进行编码,将它们看作染色体; 最后用遗传算法优化这些染色体,得到最优滤波器.理论分析和实验仿真表明,与传统基于遗传算法系数进化的IIR滤波器方法相比,基于遗传算法结构进化的IIR滤波器通带波纹缩小40.58%,过渡带宽度缩小87.62%,阻带最小衰减减少9.22%.     

高鲁棒性格型无限脉冲响应数字滤波器结构设计

针对如何设计低复杂度并对有限字长效应具有高鲁棒性的滤波器结构问题,提出了一种新型的格型无限脉冲响应（IIR）数字滤波器结构．对于一个N阶滤波器,该结构具有2N个不同的位置供输入信号选择注入．通过选择不同的位置进行注入使滤波器结构的信号功率比最小．当采用单乘法器格型单元时,提出的新结构只需2N＋1个乘法器便能实现一个N阶IIR滤波器．仿真结果表明,与传统的格型滤波器结构相比,新结构不仅需要更少的乘法器,而且具有更小的信号功率比．     

基于动态行为选择的和声搜索算法

和声搜索算法是一种模拟音乐即兴创作过程的元启发式搜索,已成功应用于解决许多实际问题.针对高维函数优化问题,提出一种基于动态行为选择的和声搜索算法.在算法中新和声的即兴创作有3种策略,迭代过程中通过计算每个策略的即时价值和综合价值选择和声的即兴创作策略,并通过个体即兴创作策略选择方法提升寻优速度或避免陷入局部最优解.将所...     

基于凝聚函数的和声搜索算法求解绝对值方程*

绝对值方程Ax-|x|=b是一个不可微的NP-hard问题。在假设矩阵A的奇异值大于1（这里矩阵A的奇异值定义为矩阵ATA特征值的非负平方根）时,给出了求解绝对值方程一个新的光滑化算法。通过引入一种凝聚函数对绝对值方程进行光滑化处理,得到一个非线性方程组;再引入适当的目标函数,进而把绝对值方程化为无约束优化问题,然后利用和声搜索算法对其进行求解。该算法模拟了音乐创作中乐师们凭借自己的记忆,通过反复调整乐队中各乐器的音调,最终达到一个美妙的和声状态的过程。数值结果表明,该算法收敛快,数值稳定性好,是求解绝对     

Pseudo-random binary sequence design for finite impulse response identification

The design of pseudo-random binary sequence (PRBS) signals for finite impulse response identification is investigated. We derive a relationship between the PRBS design parameters and the maximum eigenvalue of the parameter error covariance matrix, which yields some useful insights and design guidelines. From the perspective of minimizing the “worst-direction” error represented by the maximum eigenvalue, PRBSs are not the best test signals in the case that disturbances are colored noises. We show that by linearly combining several shifted versions of a PRBS according to the noise model, one can improve the estimation result.     

An adaptive orthogonal search algorithm for model subset selection and non-linear system identification

A new adaptive orthogonal search (AOS) algorithm is proposed for model subset selection and non-linear system identification. Model structure detection is a key step in any system identification problem. This consists of selecting significant model terms from a redundant dictionary of candidate model terms, and determining the model complexity (model length or model size). The final objective is to produce a parsimonious model that can well capture the inherent dynamics of the underlying system. In the new AOS algorithm, a modified generalized cross-validation criterion, called the adjustable prediction error sum of squares (APRESS), is introduced and incorporated into a forward orthogonal search procedure. The main advantage of the new AOS algorithm is that the mechanism is simple and the implementation is direct and easy, and more importantly it can produce efficient model subsets for most non-linear identification problems.     

Harmony filter: A robust visual tracking system using the improved harmony search algorithm

In this article a novel approach to visual tracking called the harmony filter is presented. It is based on the Harmony Search algorithm, a derivative free meta-heuristic optimisation algorithm inspired by the way musicians improvise new harmonies. The harmony filter models the target as a colour histogram and searches for the best estimated target location using the Bhattacharyya coefficient as a fitness metric. Experimental results show that the harmony filter can robustly track an arbitrary target in challenging conditions. We compare the speed and accuracy of the harmony filter with other popular tracking algorithms including the particle filter and the unscented Kalman filter. Experimental results show the harmony filter to be faster and more accurate than both the particle filter and the unscented Kalman filter.     

改进的结构进化无限冲激响应数字滤波器设计方法

为了进一步提高无限冲激击响应（IIR）数字滤波器的性能,提出了一种基于结构和参数同时进化的IIR数字滤波器设计方法。首先,通过遗传算法（GA）得到初始滤波器结构;然后,利用差分进化（DE）算法优化滤波器参数;最后,通过动态调整个体搜索步长和双向试探搜索的改进寻优算法对滤波器参数进一步优化,并将该算法用于低通、高通数字滤波器的设计。同基于遗传算法结构进化的IIR滤波器方法相比,继续利用差分进化算法和改进的寻优算法优化乘法器参数得到的低通数字滤波器的通带性能相差不大,但是过渡带宽度减小了65%,阻带最小衰减下降了36.48 dB;得到的高通数字滤波器通带波纹减少了75%,过渡带宽度减小了44%,阻带最小衰减下降了12.13 dB。实验仿真结果表明,所提方法可以获得性能更佳的滤波器,是一种有效可行的IIR数字滤波器的设计方法。     

Nonlinear system identification based on ANFIS-Hammerstein model using Gravitational search algorithm

The identification of real-world plants and processes, which are nonlinear in nature, represents a challenging problem. Currently, the Hammerstein model is one of the most popular nonlinear models. A Hammerstein model involves the combination of a nonlinear element and a linear dynamic system. On the other hand, the Adaptive-network-based fuzzy inference system (ANFIS) represents a powerful adaptive nonlinear network whose architecture can be divided into a nonlinear block and a linear system. In this paper, a nonlinear system identification method based on the Hammerstein model is introduced. In the proposed scheme, the system is modeled through the adaptation of an ANFIS scheme, taking advantage of the similarity between it and the Hammerstein model. To identify the parameters of the modeled system, the proposed approach uses a recent nature-inspired method called the Gravitational Search Algorithm (GSA). Compared to most existing optimization algorithms, GSA delivers a better performance in complex multimodal problems, avoiding critical flaws such as a premature convergence to sub-optimal solutions. To show the effectiveness of the proposed scheme, its modeling accuracy has been compared with other popular evolutionary computing algorithms through numerical simulations on different complex models.     

非线性系统广义脉冲响应函数的盲辨识

探讨减少非线性系统广义脉冲响应函数（GIRF）盲辨识所需计算量问题。 基于线性MIMO模型，应用多项式矩阵理论和子空间盲辨识技术，研究使用部分噪声向量对非线性Volterra系统的GIRF盲辨识方法。该方法的优点是能有效减少GIRF盲辨识所需的计算量。这对GIRF盲辩识方法的在线应用是有利的。仿真结果说明了这一方法的有效性。     

Harmony search algorithm and combined index-based optimal reallocation of generators in a deregulated power system

Neural Computing and Applications - It is compulsory for the electrical industry to make effective utilization of the available resources and provide a stable and reliable supply to the consumers....     

设计稳定约束最小二乘无限冲击响应滤波器的序列最小化方法

无限冲击响应(infinite impulse response, IIR)数字滤波器不具有内禀稳定性, 因此在其实际设计中要施加稳定性约束. 稳定三角形条件是一种充分必要且线性的稳定性约束条件, 为了充分利用该条件, 本文使用基于二阶因子迭代更新的序列最小化技术将IIR滤波器的约束最小二乘设计问题转化为一系列的约束最小二乘子问题, 在每一个子问题中, 有且只有一个二阶分母因子连同整个分子被优化, 其他的二阶分母因子保持不变. 设计实例表明此方法能比现有方法得到性能更好的滤波器.     

Subspace identification with constraints on the impulse response

Subspace identification methods may produce unreliable model estimates when a small number of noisy measurements are available. In such cases, the accuracy of the estimated parameters can be improved by using prior knowledge about the system. The prior knowledge considered in this paper is constraints on the impulse response. It is motivated by the availability of information about the steady-state gain, overshoot and rise time of the system, which in turn can be expressed as constraints on the impulse response. The method proposed has two steps: (1) estimation of the impulse response with linear equality and inequality constraints, and (2) realisation of the estimated impulse response. The problem on Step 1 is shown to be a convex quadratic programming problem. In the case of prior knowledge expressed as equality constraints, the problem on Step 1 admits a closed-form solution. In the general case of equality and inequality constraints, the solution is computed by standard numerical optimisation methods. We illustrate the performance of the method on a mass–spring–damper system.     

Harmony search based algorithm for the optimum design of grillage systems to LRFD-AISC

Harmony search based optimum design method is presented for the grillage systems. This numerical technique imitates the musical performance process that takes place when a musician searches for a better state of harmony. Jazz improvisation seeks to find musically pleasing harmony similar to the optimum design process which seeks to find the optimum solution. The design algorithm considers the serviceability and ultimate strength constraints which are implemented from Load and Resistance Factor Design—American Institute of Steel Construction (LRFD-AISC). It selects the appropriate W-sections for the transverse and longitudinal beams of the grillage system out of 272 discrete W-section designations given in LRFD-AISC. This selection is carried out such that the design limitations described in LRFD-AISC are satisfied and the weight of the system is the minimum. Many design examples are considered to demonstrate the efficiency of the algorithm presented.