共查询到20条相似文献,搜索用时 203 毫秒
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In this paper, a fuzzy logic controller (FLC) based variable structure control (VSC) is presented. The main objective is to obtain an improved performance of highly non‐linear unstable systems. New functions for chattering reduction and error convergence without sacrificing invariant properties are proposed. The main feature of the proposed method is that the switching function is added as an additional fuzzy variable and will be introduced in the premise part of the fuzzy rules; together with the state variables. In this work, a tuning of the well known weighting parameters approach is proposed to optimize local and global approximation and modelling capability of the Takagi‐Sugeno (T‐S) fuzzy model to improve the choice of the performance index and minimize it. The main problem encountered is that the T‐S identification method can not be applied when the membership functions are overlapped by pairs. This in turn restricts the application of the T‐S method because this type of membership function has been widely used in control applications. The approach developed here can be considered as a generalized version of the T‐S method. An inverted pendulum mounted on a cart is chosen to evaluate the robustness, effectiveness, accuracy and remarkable performance of the proposed estimation approach in comparison with the original T‐S model. Simulation results indicate the potential, simplicity and generality of the estimation method and the robustness of the chattering reduction algorithm. In this paper, we prove that the proposed estimation algorithm converge the very fast, thereby making it very practical to use. The application of the proposed FLC‐VSC shows that both alleviation of chattering and robust performance are achieved. 相似文献
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电液伺服位置系统的变结构自适应鲁棒控制 总被引:1,自引:0,他引:1
该文建立了电液伺服位置系统的带有时变参数和非线性特性的三阶模型。在此基础上。基于滑模控制理论,对其设计了一种具有参数自适应能力的自适应滑模变结构控制器。从初始状态到达滑模面这段运动时间内和在滑模面上运动时,依赖于一个时间函数使系统在两个不同的控制律之间进行切换,以满足不同运动阶段的要求。此外在应用变结构控制的同时,通过参数自适应来消除系统不确定性对控制性能的影响,进而增加了系统的鲁棒性。然后基于李亚普诺夫稳定性理论证明了所设计系统的渐近稳定性。最后将此方法应用于冷轧机电液伺服位置系统进行仿真,结果表明这种针对不同运动阶段的特点所设计的控制器满足了变结构控制的可达条件,达到了减小系统到达滑模面的时间和削弱抖振的目的。与传统的变结构控制对比。该文所设计的控制器在减小响应时间、抑止超调和提高鲁棒性方面都具有先进性。 相似文献
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针对雷达伺服系统在小信号控制时存在的爬行问题,提出了一种变结构控制方法。这种方法对系统中各种不确定性有很强的鲁棒性。它和传统的PID方法相结合可得到满意的控制效果。作者在某型雷达上进行了实验,结果表明这种方法提高了雷达伺服系统在小信号时的伺服性能。 相似文献
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Basil Mohammed Al-Hadithi Antonio Javier Barragán José Manuel Andújar Agustín Jiménez 《Applied Soft Computing》2013,13(12):4802-4812
In this paper, a fuzzy based Variable Structure Control (VSC) with guaranteed stability is presented. The main objective is to obtain an improved performance of highly non-linear unstable systems. The main contribution of this work is that, firstly, new functions for chattering reduction and error convergence without sacrificing invariant properties are proposed, which is considered the main drawback of the VSC control. Secondly, the global stability of the controlled system is guaranteed.The well known weighting parameters approach, is used in this paper to optimize local and global approximation and modeling capability of T-S fuzzy model.A one link robot is chosen as a nonlinear unstable system to evaluate the robustness, effectiveness and remarkable performance of optimization approach and the high accuracy obtained in approximating nonlinear systems in comparison with the original T-S model. Simulation results indicate the potential and generality of the algorithm. The application of the proposed FLC-VSC shows that both alleviation of chattering and robust performance are achieved with the proposed FLC-VSC controller. The effectiveness of the proposed controller is proven infront of disturbances and noise effects. 相似文献
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Dynamical adaptive integral backstepping variable structure controller design for uncertain systems and experimental application 下载免费PDF全文
Ramazan Coban 《国际强度与非线性控制杂志
》2017,27(18):4522-4540
》2017,27(18):4522-4540
In this study, a dynamical adaptive integral backstepping variable structure control (DAIBVSC) system based on the Lyapunov stability theorem is proposed for the trajectory tracking control of a nonlinear uncertain mechatronic system with disturbances. In this control scheme, no prior knowledge is required on the uncertain parameters and disturbances because it is estimated by two types of dynamical adaptive laws. These adaptive laws are integrated into the dynamical adaptive integral backstepping control and variable structure control (VSC) parts of the DAIBVSC. The dynamical adaptive law in the dynamical adaptive integral backstepping control part updates parametric uncertainties, while the other in the VSC part adapts upper bounds of non‐parametric uncertainties and disturbances. In order to achieve a more robust output tracking and better parameter adaptation, the control system is extended by one integrator and sliding surface is augmented by an integral action. Experimental evaluation of the DAIBVSC is conducted with respect to performance and robustness to parametric uncertainties. Experimental results of the DAIBVSC are compared with those of a traditional VSC. The proposed DAIBVSC exhibits satisfactory output tracking performance, good estimation of the uncertain parameters and can reject disturbances with a chattering free control law. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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基于块控原理的变结构控制 总被引:2,自引:0,他引:2
针对一类非匹配不确定性的线性系统 ,基于块控原理 ,提出了一种变结构控制设计方法 .利用反演设计方法来处理系统中的非匹配不确定性 ,再用变结构控制方法来改善系统的性能 .仿真实例证明了所提出的方法的正确性和有效性 相似文献
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Behrooz Rahmani 《International journal of systems science》2016,47(13):3180-3192
This paper is concerned with the networked control of a class of uncertain nonlinear systems. In this way, Takagi–Sugeno (T-S) fuzzy modelling is used to extend the previously proposed variable selective control (VSC) methodology to nonlinear systems. This extension is based upon the decomposition of the nonlinear system to a set of fuzzy-blended locally linearised subsystems and further application of the VSC methodology to each subsystem. To increase the applicability of the T-S approach for uncertain nonlinear networked control systems, this study considers the asynchronous premise variables in the plant and the controller, and then introduces a robust stability analysis and control synthesis. The resulting optimal switching-fuzzy controller provides a minimum guaranteed cost on an H2 performance index. Simulation studies on three nonlinear benchmark problems demonstrate the effectiveness of the proposed method. 相似文献
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Igor Škrjanc 《Journal of Intelligent and Robotic Systems》2007,49(3):237-251
This paper presents coprime-factorized model predictive control. The main idea of the proposed approach is in process-output
prediction based on a coprime-factorized process model. The proposed approach provides a framework to design the control for
a wide range of processes such as: higher order, phase non-minimal, unstable and also multivariable. In the paper the coprime-factorized
predictive design methodology was studied and implemented on unstable processes with a time-delay which are very difficult
to control. The proposed methodology leads to a simple analytical control law, which results in much better performance than
previously known control methods. 相似文献
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A modified IMC structure is proposed for unstable processes with time delays. The structure extends the standard IMC structure for stable processes to unstable processes and controllers do not have to be converted to conventional ones for implementation. An advantage of the structure is that setpoint tracking and disturbance rejection can be designed separately. A method is proposed to tune the modified IMC structure with an emphasis on the robustness of the structure. Design for some typical delayed unstable processes shows that the control structure can be tuned easily and achieve good tradeoff between time-domain performance and robustness. 相似文献
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In this paper, a proportional-integral-derivative controller in series with a lead-lag filter is designed for control of the open-loop unstable processes with time delay based on direct synthesis method. Study of the performance of the designed controllers has been carried out on various unstable processes. Set-point weighting is considered to reduce the undesirable overshoot. The proposed scheme consists of only one tuning parameter, and systematic guidelines are provided for selection of the tuning parameter based on the peak value of the sensitivity function (Ms). Robustness analysis has been carried out based on sensitivity and complementary sensitivity functions. Nominal and robust control performances are achieved with the proposed method and improved closed-loop performances are obtained when compared to the recently reported methods in the literature. 相似文献
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基于改进IMC 的开环不稳定时滞过程控制 总被引:6,自引:2,他引:6
针对开环不稳定对象,在传统内模控制结构中增加了一个预稳定控制器,提出了改进的内模控制结构,给出了闭环系统内稳定判定定理;更重要的是提出一个综合闭环性能和相角裕度的指标函数,将该指标函数最大化,可获得在不同归一化时滞情况下的优化预稳定控制器整定参数,并拟合出公式.最后,与国际上最新发表的控制方法进行了对比,显示了该方法的优越性. 相似文献
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The hybrid control scheme is proposed to stabilize the vibration of a two-link flexible manipulator while the robustness of Variable Structure Control (VSC) developed for rigid manipulators is maintained for controlling the joint angles. The VSC law alone, which is designed to accomplish only the asymptotic decoupled joint angle trajectory tracking, does not guarantee the stability of the flexible mode dynamics of the links. In order to actively suppress the flexible link vibrations, hybrid trajectories for the VSC are generated using the virtual control force concept, so that robust tracking control of the flexible-link manipulator can also be accomplished. Simulation results confirm that the proposed hybrid control scheme can achieve more robust tracking control of two-link flexible manipulator than the conventional control scheme in the presence of payload uncertainty. 相似文献
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Mariagrazia Dotoli 《Asian journal of control》2003,5(4):528-542
Variable Structure Control (VSC) has been successfully established in control systems engineering in the past two decades. Recently, Fuzzy Sliding Mode Control (FSMC) techniques have drawn the attention of the scientific community, due to their effectiveness in reducing the typical chattering phenomenon arising in VSC. In this paper we present a novel FSMC technique for a class of second order dynamical systems based on a piecewise linear sliding manifold. The proposed approach enhances the effectiveness of VSC in the presence of a saturated control input. In addition, employing the proposed VSC with fuzzy rule based algorithms results in smooth dynamics when the trajectory is in the vicinity of the switching manifold, as opposed to the typical chattering arising under classical VSC. After illustrating the proposed strategy on a simple design example, the approach is applied to an inverted pendulum, a well‐known benchmark for automatic control techniques. The effectiveness of the technique is shown both by means of simulation tests and experiments on a lab equipment. Future research directions include the extension of the technique in the presence of uncertainties in the plant model. 相似文献
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传统模糊控制的双重特性 总被引:2,自引:0,他引:2
对传统模糊控制的双重特性进行了深入探讨.定性和定量分析都显示出模糊控制
集中了相对应的线性控制和变结构滑模控制的特性.该双重特性可以通过改变属性函数和增
益来调整.高的增益和多个属性函数会导致强的变结构控制和弱的线性控制,反之亦然.仿
真结果证实了以上分析.因变结构控制更多地用于较复杂过程,而线性控制则用于较简单过
程,故独特的双重特性对模糊控制的设计和调整影响重大.对于简单过程,模糊控制的初始
增益可以用已调好的线性控制参数来设计;对于复杂过程,可用变结构控制理论来设计.模
糊控制的双重特性有助于解释其对复杂过程有较佳的鲁棒性. 相似文献
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A direct synthesis tuning method is proposed for the PI controller settings of unstable first-order-plus-time-delay processes. Unlike hitherto-known PI setting rules which often result in overshoots in time response or require the modification of the feedback control structure, this method ensures the overdamped response as desired while retaining the conventional PI control structure. This enhanced performance is possible by introducing a first-order set-point filter and applying simple rules for setting the values of the controller parameters without having any tuning parameters. The comparison with both conventional PI controllers and two-stage IMC method reveals that the proposed method produces not only smooth overdamped closed-loop response for set-point changes, but also fast regulatory control response for load changes. These responses are also shown to be quite robust against the uncertainties of the parameters as well as against the noise in the signal. The stability conditions for the processes having a large time delay or different ratios of time delay/time constant have been investigated as well. © 相似文献