共查询到20条相似文献,搜索用时 15 毫秒
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This paper addresses the implementation of an adaptive fuzzy controller for flexible link robot arms. The design technique is a hybrid scheme involving both frequency and time domain techniques. The eigenvalues of the open loop plant can be estimated through application of a frequency domain based identification algorithm. The region of the eigenvalue space, within which the system operates, is partitioned into fuzzy cells. Membership function are assigned to the fuzzy sets of the eigenvalue universe of discourse. The degree of uncertainty on the estimated eigenvalues is encountered through these membership functions. The knowledge data base consists of feedback gains required to place the closed loop poles at predefined locations. A rule based controller infers the control input variable weighting each with the value of the membership functions at the identified eigenvalue. The afore-mentioned controller is compared through simulation with conventional techniques, namely pole placement and gain scheduling. 相似文献
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In this paper, using the concept of sliding mode control SMC, a fuzzy sliding mode controller FSMC, which is synthesized by linguistic control rules, is proposed. Two sets of fuzzy rule bases are utilized to represent the controlled system. The membership functions of the THEN-part, which is used to construct a suitable equivalent control of SMC, are changed according to adaptive law. In particular, only one adaptive factor is characterized to adapt the membership functions instead of several ones in conventional adaptive approaches. Under this design scheme, we not only maintain the distribution of membership functions over state space but also reduce considerably computing time. The proposed indirect adaptive FSMC is synthesized through the following stages. First, we construct the fuzzy rule bases according to the common sense of SMC to describe the model of the controlled system, and define the fuzzy sets whose membership functions are equally distributed in state space. Then, the derived adaptive law is used to adjust the membership functions of the THEN-part to approximate an equivalent control without knowing the mathematical model of the controlled system. Third, a hitting control is developed to guarantee the stability of the control system. Finally, we smooth the hitting control via proposed heuristic control rules. We apply this FSMC to controlling a nonlinear inverted pendulum system to confirm the validity of the proposed approach. 相似文献
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In this paper, an adaptive fuzzy control approach is proposed to stabilize a class of uncertain nonlinear MIMO systems with the unmeasured states and the external disturbances. The fuzzy logic systems are used to approximate the unknown functions. Because it does not required to assume that the system states are measurable, it needs to design an observer to estimate the system unmeasured states. The considered MIMO systems are more general, i.e. they consist of N subsystems and each subsystem is in the non‐affine form. The stability of the closed‐loop system is verified by using Lyapunov analysis method. Two simulation examples are utilized to verify the effectiveness of the proposed approach. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
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H∞环路成形方法设计的控制器阶次较高,不便于工程实现和参数调整;用传统方法确定模糊控制器隶属度函数的参数和模糊规则比较费时且难以保证鲁棒性能和时频域性能指标.针对上述情况,提出了一种综合运用H∞环路成形和自适应神经模糊推理系统来设计模糊控制器的方法.首先采用H∞环路成形设计方法,得到鲁棒裕量、动态和稳态性能都符合要求的控制器,然后用自适应神经模糊推理系统来逼近此控制器,最后根据自适应神经模糊推理系统参数确定相应的模糊控制器规则和参数.该方法确定模糊控制器隶属度函数的参数精确而省时,且能保证控制器具有较强的鲁棒性和良好的控制效果.通过对小车倒立摆系统进行的仿真,验证了该控制器设计方法的有效性. 相似文献
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Fuzzy system has been known to provide a framework for handling uncertainties and imprecision by taking linguistic information from human experts. However, difficulties arise in determining effectively the fuzzy system configuration, i.e., the number of rules, input and output membership functions. A neuro‐fuzzy system design methodology by combining neural network and fuzzy logic is developed in this paper to adaptively adjust the fuzzy membership functions and dynamically optimize the linguistic‐fuzzy rules. The structure of a five‐layer feedforward network is shown to determine systematically the correct fuzzy logic rules, tune optimally (in the sense of local region) the parameters of the membership functions, and perform accurately the fuzzy inference. It is shown both numerically and experimentally that engineering applications of the neuro‐fuzzy system to vibration control have been very successful. 相似文献
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基于模糊神经网络的模型参考自适应控制 总被引:11,自引:0,他引:11
用模糊神经网络作为控制器,依靠参考模型产生理想的控制系统闭环响应,从而随时得
到控制系统的输出误差.用梯度法实时修正模糊控制器的输入和输出隶属度参数,得到一种
在线模糊自适应控制的新方法.通过倒立摆的仿真实验表明,该方法是可行的并能适应对象
特性的大范围变化. 相似文献
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针对目前国内的整平机整平精度低、抗干扰能力弱、动态响应时间长等问题,对整平机姿态控制算法进行了研究,比较并分析了PID控制和模糊控制的优缺点,设计了基于模糊PID的整平机姿态控制算法。在Matlab/Simulink仿真环境下,选定了合适的隶属度函数、模糊推理法和解模糊法,调试得出了使系统达到最优控制效果的模糊规则库。以STM32F407为处理器实现了该算法,在整平机实验平台上进行了姿态控制实验。结果表明模糊PID控制算法能够使整平机平地铲在扰动下保持良好的控制效果,控制精度和响应速度较常规PID有了大幅提升,在农业和建筑业平地系统中具有很强的应用价值。 相似文献
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基于多分辨率分析的T-S模糊系统 总被引:4,自引:0,他引:4
目前模糊系统缺乏保持辨识精度与模糊语义最佳折中的有效辨识方法,其主要原因在于缺乏系统的优化结构辨识方法.因此,本文从时-频域角度构造出基于多分辨率分析的T-S(Takagi-Sugeno)模糊系统拓扑结构.然后,采用具有多分辨率特点的B-样条尺度函构造模糊隶属函数,根据投影算法和模糊隶属函数相异测度给出了模糊系统结构辨识算法.仿真结果验证了这种模糊系统及其结构辨识算法的有效性. 相似文献
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为了提高三级倒立摆系统控制的响应速度和稳定性,在设计Mamdani型摸糊推理规则控制器控制倒立摆系统稳定的基础上,设计了一种更有效率的基于Sugeno型模糊推理规则的模糊神经网络控制器。该控制器使用BP神经网络和最小二乘法的混合算法进行参数训练,能够准确归纳输入输出量的模糊隶属度函数和模糊逻辑规则。通过与Mamdani型控制器的仿真对比,表明该Sugeno型模糊神经网络控制器对三级倒立摆系统的控制具有良好的稳定性和快速性,以及较高的控制精度。 相似文献
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自适应神经模糊推理结合PID控制的并联机器人控制方法 总被引:1,自引:0,他引:1
针对6自由度液压驱动并联机器人的精确控制问题,提出一种结合自适应神经模糊推理系统(ANFIS)和比例积分微分(PID)控制的机器人控制方法。首先,利用浮动坐标系描述法(FFRF)来模拟机器人柔性组件,并构建并联机器人的拉格朗日动力学模型。然后,根据模糊推理中的模糊规则来自适应调整PID控制器参数。最后,利用神经自适应学习算法使模糊逻辑能计算隶属度函数参数,从而使模糊推理系统能追踪给定的输入和输出数据。将该控制器与传统PID控制器、模糊PID控制器进行比较,结果表明,ANFIS自整定PID控制器大大减小了末端器位移误差,能很好的控制并联机器人末端机械手的运动。 相似文献
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针对城市固定相序的单点交叉口多相位交通信号进行控制,设计了基于车流量预测的动态调整相位最大绿灯时间的模糊控制系统。综合评估当前相位、后续相位的交通需求度,以此决定绿灯时间分配。系统采用遗传算法对模糊隶属度函数进行优化调整,使隶属函数的选取更为合理,随交通状况的改变自适应地调整。仿真结果表明,该方法能有效降低通行车辆在交叉口的平均等待时间,提高平均车流速度,控制效果明显优于传统控制方法。 相似文献
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Based on the genetic algorithm (GA), an approach is proposed for simultaneous design of membership functions and fuzzy control rules since these two components are interdependent in designing a fuzzy logic controller (FLC). With triangular membership functions, the left and right widths of these functions, the locations of their peaks, and the fuzzy control rules corresponding to every possible combination of input linguistic variables are chosen as parameters to be optimized. By using a proportional scaling method, these parameters are then transformed into real-coded chromosomes, over which the offspring are generated by rank-based reproduction, convex crossover, and nonuniform mutation. Meanwhile, the concept of enlarged sampling space is used to expedite the convergence of the evolutionary process. To show the feasibility and validity of the proposed method, a cart-centering example will be given. The simulation results will show that the designed FLC can drive the cart system from any given initial state to the desired final state even when the cart mass varies within a wide range. 相似文献