Evolutionary learning of fuzzy logic controllers and theiradaptation through perpetual evolution

This paper presents an adaptive control architecture, where evolutionary learning is applied for initial learning and real-time tuning of a fuzzy logic controller. The initial learning phase involves identification of an artificial neural network model of the process and subsequent development of a fuzzy controller with parameters obtained via a genetic search. The neural network model is utilized for evaluating trial fuzzy controllers during the genetic search. The proposed adaptive mechanism is based on the concept of perpetual evolution, where parameters of the fuzzy controller are updated at each time step with solutions extracted from a continuously evolving population of trials. There are two mechanisms that accommodate the real-time changes in the control task and/or the process into the continuous genetic search: a scheme that dynamically modifies the fitness evaluation criteria of the genetic algorithm, and an online learning of the neural network model used for evaluating the trial controllers. The potential of using evolutionary learning for real-time adaptive control is illustrated through computer simulations, where the proposed technique is applied to a chemical process control problem     

发电机组汽门系统的多模型自学习控制

针对发电机组的非线性、大范围运行等实际问题,研究了用于汽门系统的多模型自学习控制（MMSC）,首先根据各种工况下的样本数据归纳出模糊控制规则;然后由模糊聚类算法将多种工况约简为典型工况,得到相应的子模型模糊控制器（FLC）．以子模型FLC输出的加权集成作为MMSC的控制输出,而加权系数取决干子模型匹配度．在子模型FLC学习优化中,由支持向量机离线逼近模糊规则曲面,再由梯度下降算法在线自学习．仿真实验验证了所设计控制器的优良性能．     

基于遗传算法和模糊逻辑的智能飞控技术研究

设计了基于遗传算法和模糊逻辑控制的智能飞行控制系统及采用论域自调整的模糊控制器，控制器以角度跟踪误差及其微分信号为输入来控制相应的气动舵面偏转，实现对该姿态的跟踪控制。文中给出了控制器输入输出的隶属函数，设计了相应的规则库。并在此基础上进一步利用遗传算法对模糊控制器进行优化设计，给出了遗传算法各个参数的选择原则。仿真结果表明，基于遗传算法和模糊逻辑的智能飞控系统具有良好的控制效果。     

Fuzzy logic based full-envelope autonomous flight control for an atmospheric re-entry spacecraft

An intelligent and autonomous flight control system for an atmospheric re-entry vehicle is investigated, based on fuzzy logic control and aerodynamic inversion computation. A common PD-Mamdani fuzzy logic controller is designed for all the five re-entry flight regions characterized by different actuator configurations. A linear transformation to the controller inputs is applied to tune the controller performance for different flight regions while using the same fuzzy rule base and inference engine. An autonomous actuator allocation algorithm is developed, based on the aerodynamic inversion computation, to cover all the five actuator configurations with the same fuzzy logic controller. Simulation results of tracking both a bench mark trajectory and a given nominal re-entry trajectory are presented to evaluate the control performance.     

满足复杂要求的机器人最优巡回控制系统设计与实现

本文结合线性时序逻辑理论与模糊控制方法,设计并实现了一种满足复杂任务需求的移动机器人巡回控制系统,它既能够针对复杂时序任务进行路径规划,又能够对机器人进行模糊控制实现路径跟踪.首先,基于线性时序逻辑理论,确定能够满足复杂巡回任务需求的全局最优路径.接着,根据所获得的最优路径,采用模糊控制方法设计轨迹跟踪控制器,使其通过实时位姿反馈对机器人进行路径跟踪控制.仿真结果验证了移动机器人巡回控制系统的有效性.最后,基于E-Puck移动机器人构建了能够满足复杂任务需求的移动机器人巡回控制实验系统.基于所提出的最优巡回路径规划算法和模糊控制器设计方法,通过图像处理、数据通信、算法加载等软件模块的实现完成了满足复杂任务需求的移动机器人巡回控制.     

Learning fuzzy rules with tabu search-an application to control

We present an approach for the automatic definition of the fuzzy rules for a fuzzy controller based on the use of the tabu search (TS) scheme. We show also how the application of the TS process to the learning of a fuzzy rule base can be improved using heuristic symbolic meta rules. The paper is divided in two parts. The first part presents an introduction to TS and different learning schemes which can be used to apply it for the determination of the fuzzy control rules. The second part illustrates the application of the proposed techniques to a specific control problem-the parking of a truck and trailer. In particular, Section V illustrates the definition of a rule base for a static fuzzy controller, while Section VI presents the construction of an adaptive parking controller     

电动车转向系统的模糊控制仿真

本仿真的背景基于全国大学生智能车竞赛,研究电动车在随机轨迹上的跟踪转向控制。由于电动车转向控制系统的不确定性,使用传统PID控制无法满足控制需求并可能产生调节振荡。模糊控制技术基于模糊数学理论,通过模拟人的近似推理和综合决策过程,使控制算法的可控性、适应性和合理性得到提高。根据电动车转向控制的特点设计了一种简化了的模糊控制器,并与传统PID控制器进行比较。通过在MATLAB下搭建传统PID控制器模型和简化了的模糊控制器模型,最终分析和比较了该模糊控制器和传统PID控制器的不同控制效果。     

发电机组的一种多模型自学习控制

针对发电机组励磁与汽门的综合控制,研究了一种多模型自学习控制(MMSC).首先,建立机组不同工况下的样本数据并归纳模糊控制器(FLC)规则,随后采用模糊聚类算法将样本约简为典型工况,并得到对应于典型工况的模型库与控制器库.MMSC的控制量为多个FLC输出的加权集成,而加权系数由模型匹配程度决定.采用学习能力强的支持向量机来实现FLC的自学习和在线优化.仿真实验验证了MMSC的控制性能和效果.     

Designing fuzzy logic controllers using a multiresolutional searchparadigm

A multiresolutional search paradigm is employed to design optimal fuzzy logic controllers in a variable structure simulation environment. The initial search space is evaluated with a coarse resolution and some of the subspaces are selected as candidate regions for global optimum. New optimization processes are then created to investigate the candidate search spaces in detail, a process which continues until a solution is found. This search paradigm was implemented using hierarchical distributed genetic algorithms (HDGAs)-search agents solving different degrees of abstracted problems. Creation/destruction of agents is executed dynamically during the operation based on their performance. In the application to fuzzy systems, the HDGA investigates design alternatives such as different types of membership functions and the number of the fuzzy labels, as well as their optimal parameter settings, all at the same time. This paradigm is demonstrated with an application to the design of a fuzzy controller for an inverted pendulum     

Application of Fuzzy Logic Controlled Cathodic Protection on Iraq-Turkey Crude Oil Pipeline

Impressed current cathodic protection is widely used to prevent corrosion of structural steels. The major constituents, which accelerate corrosion, are resistivity, chlorides, sulfatesand the acidity (pH) of the soil. Because of these variations, the transformer-rectifier units must control and tune the output voltage depending on desired reference voltage steadily. Usually, classical controls such as PI and PID, have been widely used with their gains manually tuned based on the desired reference voltage. But, classical controls require different gains at the lower and higher end of the output voltage range to avoid overshoot and oscillation. In this study, a closed loop control system incorporating fuzzy logic has been developed for tuning output voltage of the transformer-rectifier units. The algorithm based on fuzzy logic was implemented on a modern microcontroller (PIC16F877) allowing great flexibility for various real time applications. The desired reference voltage has been given by using keypad and output values have been displayed on an LCD. It is achieved by implementing an adaptation mechanism based on fuzzy logic controller to compensate for the variations and the dynamic changes in the environment. The proposed fuzzy logic controller was applied to two different areas on Iraq-Turkey crude oil pipeline. When the performance of the proposed fuzzy logic controller was observed, it has been seen that the output voltage of transformer-rectifier unit controlled by fuzzy logic controller has no overshoot and oscillation in the both areas.     

模糊量子遗传算法及其应用

将模糊逻辑与量子理论相结合,提出了基于模糊逻辑的量子遗传算法（FQGA）。该方法使用模糊推理机指导量子门染色体更新和变异,自适应地调整量子门旋转角和变异概率。仿真结果表明：FQGA具有全局寻优能力、收敛速度快和计算时间短等优越性。     

A self-organizing fuzzy logic controller for dynamic systems usinga fuzzy auto-regressive moving average (FARMA) model

The paper proposes a complete design method for an online self-organizing fuzzy logic controller without using any plant model. By mimicking the human learning process, the control algorithm finds control rules of a system for which little knowledge has been known. In a conventional fuzzy logic control, knowledge on the system supplied by an expert is required in developing control rules, however, the proposed new fuzzy logic controller needs no expert in making control rules, Instead, rules are generated using the history of input-output pairs, and new inference and defuzzification methods are developed. The generated rules are stored in the fuzzy rule space and updated online by a self-organizing procedure. The validity of the proposed fuzzy logic control method has been demonstrated numerically in controlling an inverted pendulum     

Load control of ball mill by a high precision sampling fuzzy logic controller with self‐optimizing

A self‐optimizing, high precision sampling fuzzy logic controller for keeping a ball mill circuit working stably and efficiently is proposed in this paper. The controller is based on fuzzy logic control strategy, and a fuzzy interpolation algorithm is presented to improve the control precision. The final output of the controller is calculated through the interpolation calculation of the observation and its neighboring antecedents, and the interpolation weight coefficients are obtained according to a fuzzy inference algorithm. In the proposed controller, the sampling control strategy is used to deal with a large delay time and a controller set value which can be adjusted by a self‐optimizing algorithm, which can overcome the time‐varying characteristic. Simulation results verify that the controller can control the ball mill circuit effectively and have higher control quality. Field service results also verify that the controller can successfully optimize the control of ball mill circuit. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Various hybrid methods based on genetic algorithm with fuzzy logic controller

In this paper we propose several efficient hybrid methods based on genetic algorithms and fuzzy logic. The proposed hybridization methods combine a rough search technique, a fuzzy logic controller, and a local search technique. The rough search technique is used to initialize the population of the genetic algorithm (GA), its strategy is to make large jumps in the search space in order to avoid being trapped in local optima. The fuzzy logic controller is applied to dynamically regulate the fine-tuning structure of the genetic algorithm parameters (crossover ratio and mutation ratio). The local search technique is applied to find a better solution in the convergence region after the GA loop or within the GA loop. Five algorithms including one plain GA and four hybrid GAs along with some conventional heuristics are applied to three complex optimization problems. The results are analyzed and the best hybrid algorithm is recommended.     

Clustering categorical data sets using tabu search techniques

Clustering methods partition a set of objects into clusters such that objects in the same cluster are more similar to each other than objects in different clusters according to some defined criteria. The fuzzy k-means-type algorithm is best suited for implementing this clustering operation because of its effectiveness in clustering data sets. However, working only on numeric values limits its use because data sets often contain categorical values. In this paper, we present a tabu search based clustering algorithm, to extend the k-means paradigm to categorical domains, and domains with both numeric and categorical values. Using tabu search based techniques, our algorithm can explore the solution space beyond local optimality in order to aim at finding a global solution of the fuzzy clustering problem. It is found that the clustering results produced by the proposed algorithm are very high in accuracy.     

Single-chip fuzzy logic controller design and an application on a permanent magnet dc motor

This paper describes a low-cost single-chip PI-type fuzzy logic controller design and an application on a permanent magnet dc motor drive. The presented controller application calculates the duty cycle of the PWM chopper drive and can be used to dc–dc converters as well. The self-tuning capability makes the controller robust and all the tasks are carried out by a single chip reducing the cost of the system and so program code optimization is achieved. A simple, but effective algorithm is developed to calculate numerical values instead of linguistic rules. In this way, external memory usage is eliminated. The contribution of this paper is to present the feasibility of a high-performance non-linear fuzzy logic controller which can be implemented by using a general purpose microcontroller without modified fuzzy methods. The developed fuzzy logic controller was simulated in MATLAB/SIMULINK. The theoretical and experimental results indicate that the implemented fuzzy logic controller has a high performance for real-time control over a wide range of operating conditions.     

多输入–多输出非线性系统的特征模型及在挠性卫星姿态控制中的应用

研究多输入–多输出（MIMO）高阶非仿射非线性系统的特征建模问题.首先证明了MIMO高阶非仿射非线性系统的特征模型可用二阶时变差分方程组描述,并给出了特征模型的建模误差.然后设计了基于特征模型的自适应模糊广义预测控制器,利用Lyapunov方法分析了闭环系统的稳定性.由于控制结构中使用了分层模糊逻辑系统,从而极大减少了模糊规则和可调参数的个数,提高了控制的实时性.通过对挠性卫星姿态控制的仿真研究验证了所给控制方案的有效性,可实现高精度的姿态控制,且该方法具有较强的鲁棒性.     

基于改进量子粒子群算法的NCS模糊控制器参数优化

针对网络化控制系统中模糊控制器的量化因子和比例因子采用传统经验方法难以整定的问题, 提出了一种改进量子粒子群（IQPSO）算法对模糊控制器量化因子和比例因子进行优化。该方法将ABC算法中的搜索算子作为变异算子引入到QPSO算法中, 使得IQPSO算法较好地克服了QPSO算法保持种群多样性差容易早熟收敛的缺陷, 并以ITAE指标作为IQPSO算法的适应度函数对模糊控制器进行优化。典型工业过程仿真结果表明, IQPSO优化的模糊控制器具有比PID控制器和标准QPSO优化的模糊控制器更好的控制性能和适用性。