共查询到10条相似文献,搜索用时 78 毫秒
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The paper addresses the adaptive behaviour of parallel fuzzy proportional plus fuzzy integral plus fuzzy derivative (FP+FI+FD) controller. The parallel FP+FI+FD controller is actually a non-linear adaptive controller whose gain changes continuously with output of the process under control. Two non-stationary processes, whose characteristics change with time, are considered for simulation study. Simulation is performed using software LabVIEW TM . The set-point tracking response of parallel FP+FI+FD is compared with conventional parallel proportional plus integral plus derivative (PID) controller, tuned with the Ziegler-Nichols (Z-N) tuning technique. Simulation results show that conventional PID controller fails to track the set-point and becomes unstable as the process changes its characteristic with time. But the parallel FP+FI+FD controller shows considerably much better set-point tracking response and does not deviate from steady state. Also, a huge spike is observed in the output of PID controller as the reference set-point and process parameters are changed, while the FP+FI+FD controller gives spike free control signal. 相似文献
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In this paper, a parallel fuzzy proportional plus fuzzy integral plus fuzzy derivative (FP+FI+FD) controller is proposed. It is derived from the conventional parallel proportional-integral-derivative (PID) controller. It preserves the linear structure of a conventional parallel PID controller, with analytical formulas. The final shape of the controller is a discrete-time fuzzy version of a conventional parallel PID controller. Computer simulations are performed to evaluate the performance of the FP+FI+FD controller for setpoint tracking and load-disturbance rejection for some complex processes, such as first- and second-order processes with delay, inverse response process with and without delay and higher order processes. Also, the performance of the proposed fuzzy controller is evaluated experimentally on highly nonlinear liquid-flow process with a hysteresis characteristic due to a pneumatic control valve. The simulation and real time control is done using National Instrument hardware and software (LabVIEW). The response of the FP+FI+FD controller is compared with the conventional parallel PID controller, tuned with the Ziegler-Nichols (Z-H) and Astrom-Hagglund (A-H) tuning technique. It is observed that the FP+FI+FD controller performed much better than the conventional PI/PID controller. Simulation and experimental results demonstrate the effectiveness of the proposed parallel FP+FI+FD controller. 相似文献
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模糊PID控制器的稳定性分析 总被引:2,自引:0,他引:2
构造出一种PID型模糊控制器,并证明了这种模糊控制器近似于一种变参数的PID控制器,以PID模型为基础,基于无源性定量对模型PID控制器的稳定性进行分析,导出了使模糊PID控制器稳定的充分条件,为设计稳定的模糊PID控制器提供了理论指导。 相似文献
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A fuzzy PID controller for nonlinear and uncertain systems 总被引:9,自引:0,他引:9
J. H. Kim S. J. Oh 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2000,4(2):123-129
In order to control systems that contain nonlinearities or uncertainties, control strategies must deal with the effects of
these. Since most control methods based on mathematical models have been mainly focused on stability robustness against nonlinearities
or uncertainties, they are limited in their ability to improve the transient responses. In this paper, a nonlinear fuzzy PID
control method is suggested, which can stably improve the transient responses of systems disturbed by nonlinearities or unknown
mathematical characteristics. Although the derivation of the control law is based on the design procedure for general fuzzy
logic controllers, the resultant control algorithm has analytical form with time varying PID gains rather than linguistic
form. This means the implementation of the proposed method can be easily and effectively applied to real-time control situations.
Control simulations are carried out to evaluate the transient performance of the suggested method through example systems,
by comparing its responses with those of the nonlinear fuzzy PI control method developed in [9]. 相似文献
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In this paper, we present two sufficient conditions in the frequency domain for the global stability analysis of the simplest Takagi-Sugeno (T-S) fuzzy control system, based on the circle criterion and its graphical interpretation. These conditions are significant in graphically designing the simplest T-S fuzzy controller in the frequency domain. Four numerical examples are provided to demonstrate the efficiency of our two frequency domain-based conditions. Furthermore, this T-S fuzzy controller and the linear proportional controllers are also compared. It is concluded that the simplest T-S fuzzy controller can outperform the linear proportional controllers in a noisy environment with external disturbances. 相似文献
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一类T-S模糊控制系统的稳定性分析及设计 总被引:1,自引:0,他引:1
研究了一类输入采用双交叠模糊分划的T-S模糊控制系统稳定性分析及控制器设计问题.基于分段模糊Lyapunov函数,提出了一个新的判定开环T-S模糊系统稳定性的充分条件,该方法只需在各个模糊区间里满足模糊Lyapunov方法中的条件,其保守性比公共Lyapunov函数法和分段Lyapunov函数法的保守性更低.运用并行分布补偿法(PDC)进一步探讨了闭环T-S模糊控制系统的稳定性分析问题并设计了模糊控制器.最后,一个仿真示例说明了本文方法的有效性. 相似文献
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