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1.
Pneumatic Artificial Muscle (PAM) actuator has been widely used in medical and rehabilitation robots, owing to its high power-to-weight ratio and inherent safety characteristics. However, the PAM exhibits highly non-linear and time variant behavior, due to compressibility of air, use of elastic-viscous material as core tube and pantographic motion of the PAM outer sheath. It is difficult to obtain a precise model using analytical modeling methods. This paper proposes a new Artificial Neural Network (ANN) based modeling approach for modeling PAM actuator. To obtain higher precision ANN model, three different approaches, namely, Back Propagation (BP) algorithm, Genetic Algorithm (GA) approach and hybrid approach combing BP algorithm with Modified Genetic Algorithm (MGA) are developed to optimize ANN parameters. Results show that the ANN model using the GA approach outperforms the BP algorithm, and the hybrid approach shows the best performance among the three approaches.  相似文献   

2.
有监督联想型人工神经网络优化算法的归纳与应用   总被引:1,自引:0,他引:1  
归纳了有监督学习联想人工神经网络的一般算法,提出其优化算法.详细分析Hebb规则和仿逆规则,并对这两种规则进行全面对比.研究了有监督学习联想人工神经网络的一般算法,指出算法中的两个分支点,从而确定仿逆规则在一定程度上优于Hebb规则.介绍了Hamming距离的概念,提出两向量相似度的概念.总结了有监督学习联想人工神经网络的优化算法.利用此优化算法对数字符号图像识别问题进行仿真研究,研究结果以数据表示.  相似文献   

3.
Analog Integrated Circuits and Signal Processing - Chimp optimization algorithm (ChOA) is a robust nature-inspired technique, which was recently proposed for addressing real-world challenging...  相似文献   

4.
In this study, a saliency-directed color image interpolation approach using artificial neural network (ANN) and particle swarm optimization (PSO) is proposed. First, a high-quality saliency map of a color image to be interpolated is generated by a modified block-based visual attention model in an effective manner. Then, based on the saliency map, bilinear interpolation and ANN-PSO interpolation are employed for non-saliency (non-ROI) and saliency (ROI) blocks, respectively, to obtain the final color interpolation results. In the proposed ANN-PSO interpolation scheme, ANN is used to determine the orientation of each 5 × 5 image pattern (block), whereas PSO is employed to determine the weights in 5 × 5 interpolation filtering masks. The proposed approach is applicable to image interpolation with arbitrary magnification factors (MFs). Based on the experimental results obtained in this study, the color interpolation results by the proposed approach are better than those by five comparison approaches.  相似文献   

5.
提出了一种单相并联混合型有源电力滤波器的电路结构.该电路由有源滤波器与基波串联谐振支路并联再与无源滤波电路串联构成,用于抑制非线性整流负载产生的谐波电流流入电源侧.在该电路中,无源滤波器分担大部分抑制谐波和无功补偿的任务,减少了有源滤波器的容量;有源电力滤波器用于改善无源滤波器的滤波效果,抑制它与系统阻抗可能发生的谐振.实验结果表明,该混合型有源滤波器充分发挥了无源滤波器和有源滤波器各自优点,改善了无源滤波器的滤波性能,同时使有源滤波器不再承受基波电压,最大限度地减少了有源滤波器的容量,从而使有源电力滤波器可应用于大功率场合.  相似文献   

6.
针对数字开关电源的控制策略问题,提出一种改进共轭梯度算法的BP神经网络PID控制系统.以BUCK变换器为研究对象,在BP神经网络PID算法的基础上,通过改进共轭梯度算法优化控制系统的调节时间和恢复速度,以提高数字开关电源系统的控制性能和输出性能.基于MATLAB软件完成系统建模进行仿真研究.结果表明:改进后的控制系统比...  相似文献   

7.
近年来,随着人工神经网络在信息、自动化、医学、经济等领域的广泛应用和杰出表现,使得人工神经网络又开始得到广泛关注和重新重视。基于需求,本文对人工神经网络做了简单概述。  相似文献   

8.
基于遗传算法优化BP神经网络的风电功率预测   总被引:1,自引:0,他引:1  
随着大量风电开始并入电网,风电场输出功率预测对接入大量风电的电力系统的运行有重要意义。针对神经网络在风电功率预测中结构和权值参数难以确定,预测精度不高等问题,提出利用遗传算法对神经网络的拓扑结构和网络权值进行优化,并将其应用于风电场功率预测,研究表明预测精度有一定程度的提高。  相似文献   

9.
This paper reviews the current use of spectroscopy and related instrumentation in chemical analysis. Advancements in digital signal processing technology are making it possible to improve the sensitivity and accuracy of analytical instruments without expensive upgrading of instrument hardware. A hybrid neural network (HNN) is described that can perform nonlinear signal analysis. The HNN approach combines the simple data reduction capability of conventional linear signal processing algorithms with the adaptive learning and recognition ability of a multilayer nonlinear neural network architecture. A number of examples show the rise of the HNN for environmental monitoring and real-time process control  相似文献   

10.
分析混合有源电力滤波器的补偿原理和补偿特性,该滤波器能够很好地改善无源滤波器的滤波性能,实现大功率下的谐波抑制和无功功率补偿。最后,建立仿真模型,并对波形作出分析。  相似文献   

11.
混合有源电力滤波器的仿真研究   总被引:2,自引:0,他引:2  
分析混合有源电力滤波器的补偿原理和补偿特性,该滤波器能够很好地改善无源滤波器的滤波性能,实现大功率下的谐波抑制和无功功率补偿.最后,建立仿真模型,并对波形作出分析.  相似文献   

12.
This paper describes a novel technique for the cancellation of the ventricular activity for applications such as P-wave or atrial fibrillation detection. The procedure was thoroughly tested and compared with a previously published method, using quantitative measures of performance. The novel approach estimates, by means of a dynamic time delay neural network (TDNN), a time-varying, nonlinear transfer function between two ECG leads. Best results were obtained using an Elman TDNN with nine input samples and 20 neurons, employing a sigmoidal tangencial activation in the hidden layer and one linear neuron in the output stage. The method does not require a previous stage of QRS detection. The technique was quantitatively evaluated using the MIT-BIH arrhythmia database and compared with an adaptive cancellation scheme proposed in the literature. Results show the advantages of the proposed approach, and its robustness during noisy episodes and QRS morphology variations.  相似文献   

13.
Active power filter with hybrid energy storage   总被引:1,自引:0,他引:1  
An active power filter that uses an impressed current converter and an inductive-capacitive energy storage circuit is presented. This storage includes a switching section to interface the inductive and capacitive element. This solution allows independent choice of the converter configuration and of the type of storage system which, in this particular case, is mainly capacitive. The theory of operation is analyzed, together with control strategy and design criteria. Experimental results are reported  相似文献   

14.
进化计算与人工神经网络的结合   总被引:6,自引:1,他引:6  
进化计算和人工神经网络作为两个工具在众多的研究领域得到了广泛应用。进化计算和人工神经网络本身也得到了很大的发展。类似于生物神经网络,人工神经网络( A N N) 由一些简单的处理单元组成,这些单元通过权值的连接而相互作用。 A N N 因其鲁棒性、并行性及学习能力受到特别的重视。进化计算体现了生物进化中的四个要素,即:繁殖、变异、竞争和自然选择。目前泛指各种基于生物进化原理的仿真计算方法的总称。文中首先介绍了进化计算的有关概念,包括遗传算法、进化策略等,其次就其与人工神经网络技术相结合的方法作了进一步分析探讨。主要集中于进化的网络结构设计、进化的网络训练及其它结合方法等方面的有关问题。  相似文献   

15.
单明  周步祥 《信息技术》2006,30(6):62-65
提出了一种人工神经网络与灰色理论模型相结合的综合预测方法。在神经网络结构设计中分别选取带有横向和纵向特征的负荷作为输入,并充分考虑气候敏感因素及特殊负荷日的影响。在分析预测差值的基础上,将灰色理论残差校正模型运用到预测结果的修正当中去。算例表明所提出的方法提高了预测精度。  相似文献   

16.
吴文博  吴雷 《电子设计工程》2013,21(8):99-101,104
为了提高混合型有源电力滤波器(Hybrid Active Power Filter,HAPF)的电流检测方法的性能,提出一种基于自适应有限脉冲响应(FIR)预测与FBD电流检测相结合的电流检测算法。通过对注入式混合型有源滤波器(IHAPF)结构及工作原理的分析,将算法应用于该装置谐波电流检测环节。最后采用Matlab对模型进行仿真分析,试验结果证明复合算法理论的正确性。  相似文献   

17.
For active contour modeling (ACM), we propose a novel self-organizing map (SOM)-based approach, called the batch-SOM (BSOM), that attempts to integrate the advantages of SOM- and snake-based ACMs in order to extract the desired contours from images. We employ feature points, in the form of an edge-map (as obtained from a standard edge-detection operation), to guide the contour (as in the case of SOM-based ACMs) along with the gradient and intensity variations in a local region to ensure that the contour does not "leak" into the object boundary in case of faulty feature points (weak or broken edges). In contrast with the snake-based ACMs, however, we do not use an explicit energy functional (based on gradient or intensity) for controlling the contour movement. We extend the BSOM to handle extraction of contours of multiple objects, by splitting a single contour into as many subcontours as the objects in the image. The BSOM and its extended version are tested on synthetic binary and gray-level images with both single and multiple objects. We also demonstrate the efficacy of the BSOM on images of objects having both convex and nonconvex boundaries. The results demonstrate the superiority of the BSOM over others. Finally, we analyze the limitations of the BSOM.  相似文献   

18.
神经网络图像识别技术是随着当代计算机技术、图像处理、人工智能、模式识别理论等发展起来的一种新型图像识别技术。在进行图像识别之前需要利用数字图像处理技术进行图像预处理以及特征提取。本文选取字符图像0~9作为识别目标,对图像预处理过程进行了叙述,并在此基础上选取字符图像矩阵每行的与每列的黑色像素点之和以及图像欧拉数这两个特征作为BP神经网络的输入样本。经实验仿真表明图像的平均识别率为89%,这表明图像预处理的结果和提取的特征是合适的、有效的,设计的BP网络也较好的完成了模式分类识别工作。  相似文献   

19.
本文以某干旱地区的河流为典型研究对象,通过构建人工神经网络的方法,对该河流的水文情况进行预测.研究结果显示,本文中所采用的BP神经网络及其算法具有较好的精度和稳定性,可用于该地区今后水文情况的预测,同时也可为其他地区的相关工作提供参考借鉴.  相似文献   

20.
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