共查询到20条相似文献，搜索用时 15 毫秒
1.
领域或现场的可编程门阵列是一种新型可编程逻辑器件,它具有大容量、小时延、易改进和灵活性等特点,基于神经模糊系统原理,本文提出了一种基于VCN模糊数值算法的FPGA技术方案。该算法采用了一种VCR运算路径可重复使用技术、中间结果可变形处理及存放于RAM中实现的方法。经深入研究和试验分析,该算法是切实可行的。 相似文献
2.
A maximum power point tracker for photovoltaic energy systems based on fuzzy neural networks 总被引：1，自引：0，他引：1
Chun-hua Li Xin-jian Zhu Guang-yi Cao Wan-qi Hu Sheng Sui Ming-ruo Hu 《浙江大学学报(A卷英文版)》2009,10(2):263-270
To extract the maximum power from a photovoltaic （PV） energy system, the real-time maximum power point （MPP） of the PV array must be tracked closely. The non-linear and time-variant characteristics of the PV array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP for traditional control strategies. We propose a fuzzy neural network controller （FNNC）, which combines the reasoning capability of fuzzy logical systems and the learning capability of neural networks, to track the MPP. With a derived learning algorithm, the parameters of the FNNC are updated adaptively. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the FNNC. Simulation results show that the proposed control algorithm provides much better tracking performance compared with the filzzy logic control algorithm. 相似文献
3.
粒子群优化算法是基于群智能的随机优化算法,目前已广泛应用于神经网络、非线性函数优化、模式分类、模糊系统控制等,特别适合工程应用。本文首先介绍传统的PSO算法原理及算法流程,最后用VB语言实现算法的伪码。 相似文献
4.
In order to improve the output efficiency of a photovoltaic (PV) energy system, the real-time maximum power point (MPP) of the PV array should be tracked closely. The non-linear and time-variant characteristics of the photovoltaic array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP as in traditional control strategies. A neural fuzzy controller (NFC) in conjunction with the reasoning capability of fuzzy logical systems and the learning capability of neural networks is proposed to track the MPP in this paper. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the NFC. With a derived learning algorithm, the parameters of the NFC are updated adaptively. Experimental results show that, compared with the fuzzy logic control algorithm, the proposed control algorithm provides much better tracking performance. 相似文献
5.
Study on the Fuzzy COntrol Strategy of Automobile with CVT 总被引：3，自引：0，他引：3
In order to study the dynamic characteristics of automobile with a CVT system, a bond graph analysis model of continuously variable transmission is established.On the base of the simulation state space equations that are established with bond graph theory,a fuzzy control strategy with an expert system of starting process has been introduced.Considering uncertain system parameters and exterior resistance disturbing,the effect of the profile of membership function and the defuzzification algorthm on the capacity of the fuzzy controller has been studied.The result of simulation proves that the proposed fuzzy controller is effective and feasible,Such controller has been employed in the actual control and has proved practicable.The study lays a foundation for design of the fuzzy controller for automobile with a CVT system. 相似文献
6.
SU Cheng-li WANG Shu-qing 《浙江大学学报(A卷英文版)》2006,7(10):1723-1732
INTRODUCTION In recent years, research on nonlinear model predictive control has attracted significant attention because most practical processes are nonlinear. In industry process control, model predictive controllers based on linear models (LMPC) are often used to control nonlinear systems. When the operating con- ditions undergo significant changes, the performance of LMPC can deteriorate drastically. Under such conditions, predictive control based on nonlinear models (NMPC) shoul… 相似文献
7.
针对大多数复杂热工控制对象非线性特性与运行工况密切相关的实际特点,提出了一种基于模糊加权的多模型预测控制算法。该算法采用多模型自适应控制（MMAC）中模型集选取的方法,权重计算则通过多模型优化模糊加权算法,将各子模型输出概率加权平均值作为对实际对象的预测输出值,通过一个动态矩阵预测控制器计算最终控制。并对一个超临界600MW直流锅炉过热汽温对象进行仿真,验证了该算法的有效性。 相似文献
8.
Design of general multivariable process controllers is an attractive and practical alternative to optimizing design by evolutionary algorithms （EAs） since it can be formulated as an optimization problem. A closed-loop particle swarm optimization （CLPSO） algorithm is proposed by mapping PSO elements into the closed-loop system based on control theories. At each time step, a proportional integral （PI） controller is used to calculate an updated inertia weight for each particle in swarms from its last fitness. With this modification, limitations caused by a uniform inertia weight for the whole population are avoided, and the particles have enough diversity. After the effectiveness, efficiency and robustness are tested by benchmark functions, CLPSO is applied to design a multivariable proportional-integral-derivative （PID） controller for a solvent dehydration tower in a chemical plant and has improved its performances. 相似文献
9.
1Introduction Moltencarbonatefuelcell(MCFC)isaclearelec tricitygeneratingtechniquewithhighefficiency,which istobeusedwidely.Withoutcombustion,MCFCcon vertschemicalenergycontainedinfuelandoxidantin toelectricenergyviaelectro chemicalreaction.Per formanceof… 相似文献
10.
LIU Cheng-ze ZHU Xin-jian 《浙江大学学报(A卷英文版)》2006,7(11):1878-1885
INTRODUCTION Proton Exchange Membrane Fuel Cell (PEMFC) is being rapidly developed in recent years because of its compact structure, light weight, low working temperature and rapid startup characteristics. But its E-I characteristic curve reveals its decreasing per- formance when confronted with suddenly increasing power demand, and high cost also restrains the ap- plication of the fuel cell. So the hybrid power scheme is the most suitable selection presently. Most of researches on fu… 相似文献
11.
This paper discusses a kind of optimal method used for searching flat panel display (FPD) scanning matrix. The method adopts
bionic algorithm: genetic algorithm (GA) and particle swarm optimization (PSO) algorithm. The method using single GA is more
time-consuming, and the search efficiency is low in later evolution; the PSO algorithm is easily falling into the local optimal
solution and appears the premature convergent phenomenon. Hence, a hybrid approach of GAPSO is found to optimize the search
for high grayscale weights scanning matrix. Finally in the acceptable time, it finds a weight scanning matrix (WSM) of 256
gray scales with Matlab, whose scanning efficiency reaches 94.73% and the linearity is very good. 相似文献
12.
INTRODUCTION Saccharomycete, closely linked with human life, is the only microbe that has been utilized to the extent of over a million tons in the world, and is one of the modelled biological bacteria mostly used in modern genetic engineering. Since there are no effective online instruments for measuring the production or resultant concentration, which is a very important quality index in fermentation process, soft sensors (Martin, 1997; Tham et al., 1991; Assis and Filho, 2000; Salgad… 相似文献
13.
徐君鹏 《河南科技学院学报》2007,35(3):62-65
Fuzzy systems are currently being used in a wide field of industrial and scientific applications. Since the design and especially the optimization process of fuzzy systems can be very time consuming, it is convenient to have algorithms which construct and optimize them automatically. In order to improve the system stability and raise the response speed, a new control scheme, direct - torque neuro - fuzzy control for induction motor drive, was put forward. The design and tuning procedure have been described. Also, the improved stator flux estimation algorithm, which guarantees eccentric estimated flux has been proposed. 相似文献
14.
The operating temperature of a solid oxide fuel cell （SOFC） stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative （PID） control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC. 相似文献
15.
The permutation flowshop scheduling problem (PFSP) is one of the most well-known and well-studied production scheduling problems with strong industrial background. This paper presents a new hybrid optimization algorithm which combines the strong global search ability of artificial immune system (AIS) with a strong local search ability of extremal optimization (EO) algorithm. The proposed algorithm is applied to a set of benchmark problems with a makespan criterion. Performance of the algorithm is evaluated. Comparison results indicate that this new method is an effective and competitive approach to the PFSP. 相似文献
16.
应用于液压集成块优化的一种混合遗传-退火算法 总被引：1，自引：0，他引：1
This paper establishes a mathematical model of multi-objective optimization with behavior constraints in solid space based on the problem of optimal design of hydraulic manifold blocks (HMB). Due to the limitation of its local search ability of genetic algorithm (GA) in solving a massive combinatorial optimization problem, simulated annealing (SA) is combined, the multi-parameter concatenated coding is adopted, and the memory function is added. Thus a hybrid genetic-simulated annealing with memory function is formed. Examples show that the modified algorithm can improve the local search ability in the solution space, and the solution quality. 相似文献
17.
模糊子集参数是模糊控制的重要参数之一。针对模糊子集参数获得的盲目性,用SAGACIA优化方法对其进行优化;并且对模糊子集参数编码方式进行了改进,既保证了模糊子集隶属函数的完备性,又保证了其语义性。 相似文献
18.
Electrical discharge machining （EDM） process, at present is still an experience process, wherein selected parameters are often far from the optimum, and at the same time selecting optimization parameters is costly and time consuming. In this paper, artificial neural network （ANN） and genetic algorithm （GA） are used together to establish the parameter optimization model. An ANN model which adapts Levenberg-Marquardt algorithm has been set up to represent the relationship between material removal rate （MRR） and input parameters, and GA is used to optimize parameters, so that optimization results are obtained. The model is shown to be effective, and MRR is improved using optimized machining parameters. 相似文献
19.
Hybrid discrete particle swarm optimization algorithm for capacitated vehicle routing problem 总被引：11，自引：0，他引：11
CHEN Ai-ling YANG Gen-ke WU Zhi-ming 《浙江大学学报(A卷英文版)》2006,7(4):607-614
INTRODUCTION The vehicle routing problem (VRP), which was first introduced by Dantzig and Ramser (1959), is a well-known combinatorial optimization problem in the field of service operations management and logis- tics. The capacitated vehicle routing problem (CVRP) is an NP-hard problem for simultaneously determining the routes for several vehicles from a central depot to a set of customers, and then return to the depot without exceeding the capacity constraints of each vehicle. In pr… 相似文献
20.
1 Introduction Support vector machine (SVM) is a powerful ma-chine learning tool capable of representing non-linearrelationships and producing models that generalizeswell to unseen data .SVMhave been applied widelyinmany fields[1]such as hand-written character recogni-tion ,text categorization,computer vision,speechrec-ognition and gene classification,etc. Despite this , using an SVM requires a certainamount of model selection,i.e.,selection of the ac-tual kernel and its parameters .In rec… 相似文献