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1.
    
In this paper, the problem of adaptive fuzzy finite-time consensus tracking control for multiple Euler-Lagrange systems (ELSs) with uncertain dynamics and unknown control directions (UCDs) is investigated. The computational complexity problem in conventional backstepping is avoided by using finite-time command filter (FTCF), and the error in the filtering process is eliminated through error compensation signals. The fuzzy logic system combined with the adaptive control technique is applied to approximate and estimate the unknown nonlinear dynamics of ELS. The Nussbaum function-based continuous and nonsmooth input control torque is established to eliminate the influence of UCDs, and the proposed control scheme can guarantee the consensus tracking errors converge to the desired neighborhood of the origin within a finite time. Numerical simulation is used to test the effectiveness of the given algorithm.  相似文献   

2.
    
This article is mainly concentrated on the predefined-time adaptive fuzzy control of stochastic nonlinear systems. To handle nonlinear functions that are uncertain, fuzzy logic systems (FLSs) are used to approximate them. Compared with the existing studies, a Lyapunov-type criterion for practically predefined-time stochastic stabilization (PPSS) is put forward to guarantee the stabilization of the system. The stabilization time is merely dependent on one design parameter, which means the parameter can be adjusted to set the stability time.  相似文献   

3.
    
The article investigates the finite-time adaptive fuzzy control for a class of nonlinear systems with output constraint and input dead-zone. First, by skillfully combining the barrier Lyapunov function, backstepping design method, and finite-time control theory, a novel adaptive state-feedback tracking controller is constructed, and the output constraint of the nonlinear system is not violated. Second, the fuzzy logic system is used to approximate unknown function in the nonlinear system. Third, the finite-time command filter is introduced to avoid the problem of “complexity explosion” caused by repeated differentiations of the virtual control signal in conventional backstepping control schemes. Meanwhile, a new saturation function is added in the compensating signal for filter error to improve control accuracy. Finally, based on Lyapunov stability analysis, all the signals of the closed-loop are proved to be semi-globally uniformly ultimately bounded, and the tracking error converges to a small neighborhood region of the origin in a finite time. A simulation example is presented to demonstrate the effectiveness for the proposed control scheme.  相似文献   

4.
    
In this article, the fuzzy adaptive finite-time consensus tracking control problem for nonstrict feedback nonlinear multiagent systems with full-state constraints is studied. The finite-time control based on command filtered backstepping is proposed to guarantee the finite-time convergence and eliminate the explosion of complexity problem caused by backstepping process, and the errors in the filtering process are compensated by using error compensation mechanism. Furthermore, based on the fuzzy logic systems, the uncertain nonlinear dynamics are approximated and the problem of state variables in nonstrict feedback form is solved by using the property of basis functions. The barrier Lyapunov functions are introduced to guarantee that all system states and compensated tracking error signals are constrained in the designed regions. A simulation example is given to verify the superiority of the proposed algorithm.  相似文献   

5.
    
The trajectory tracking control problem for a class of nonlinear systems with uncertain parameters is considered in this article. A new adaptive finite-time tracking control is designed based on the adaptive backstepping method via the command filters. The command filter mechanism can avoid the calculation of partial derivatives and solve the “explosion of complexity” in the backstepping design. The compensation signals are introduced to eliminate errors produced by the command filters. The proposed adaptive backstepping control can guarantee the tracking error remains in a small neighborhood of the origin in finite time, while the practical finite-time stability of the control systems with uncertain parameters is proven by the stability criterion. The effectiveness of the proposed scheme is verified by some simulation results.  相似文献   

6.
    
In this article, we address the problem of achieving predefined-time control for a class of nonlinear dynamical systems with parameter uncertainties. We introduce an adaptive predefined-time control algorithm based on integrator backstepping for n $$ n $$th order nonlinear systems. Using Lyapunov's stability theory, we establish that the proposed predefined time control approach, combined with an adaptive law, ensures the boundedness of all signals within the closed-loop system. A notable advantage of our method is its potential to achieve convergence within a predetermined time frame. To validate our approach's efficacy, we present a practical example involving a 2 DOF helicopter, demonstrating the effectiveness of the proposed scheme.  相似文献   

7.
首先简要介绍了OPC技术,然后通过分析除尘系统的特点,将OPC技术应用到除尘系统中,回收粉尘,并给出了相应的控制策略,设计了相关的程序模块。利用WINCC组态模拟现场画面,操作界面简单明了,方便易用。并给出了利用OPC技术实现wincc与s7—200的通讯过程。实际应用表明由OPC技术构成的控制系统具有成本低廉、经济实用,可靠性高等特点.  相似文献   

8.
    
In this article, the problem of output feedback tracking control for uncertain Markov jumping nonlinear systems is studied. A finite-time control scheme based on command filtered backstepping and adaptive neural network (NN) technique is given. The finite-time command filter solves the problem of differential explosions for virtual control signals, the NN is utilized to approximate the uncertain nonlinear dynamics and the adaptive NN observer is applied to restructure the state of system. The finite-time error compensation mechanism is established to compensate the errors brought by filtering process. The proposed finite-time tracking control algorithm can ensure that the solution of the closed-loop system is practically finite-time stable in mean square. Two simulation examples are employed to demonstrate the effectiveness of the proposed control algorithm.  相似文献   

9.
随着多电化和全电化趋势的发展,飞机电气与电子设备大量增加,恒频系统已不能满足飞机用电需求。飞机供电体制需要由恒频系统向变频系统转变,而变频发电机是变频系统中尤为重要的设备。传统的PID控制采用固定参数,无法很好地在宽变频发电系统中工作,因此提出了基于模糊反步自适应控制算法的控制参数修正方法以提高调压系统适应性。结合三级式发电系统数学模型,设计了调压系统中不确定参数的自适应律分析方法,并建立了基于该算法的调压系统仿真模型。通过仿真验证了模糊反步自适应控制可以有效抑制工作条件变化对调压系统造成的影响,增强调压系统的稳定性和调节性能,为飞机发电机控制器的设计提供理论支持。  相似文献   

10.
针对伺服系统中普遍存在的机械谐振问题,建立了系统的状态方程模型。将与机械谐振密切相关的系统参数设为不确定变量,采用自适应模糊逻辑系统在线估计包含这些参数的非线性环节,并基于反步法设计了自适应模糊控制器,有效地抑制了伺服系统中机械谐振的影响。采用李雅普诺夫方法证明了伺服系统位置跟踪误差的指数收敛性。仿真实验表明本方法具有很好的自适应性能,能够减小系统传递力矩的振荡,显著提高伺服跟踪的精确度和动态性能。  相似文献   

11.
    
This article investigates the issue of adaptive finite-time tracking control for a category of output-constrained nonlinear systems in a non-strict-feedback form. First, by utilizing the structural characteristics of radial basis function neural networks (RBF NNs), a backstepping design method is extended from strict-feedback systems to a kind of more general systems, and NNs are employed to approximate unknown nonlinear functions. In addition, the system output is constrained to the specified region by applying the barrier Lyapunov function (BLF) technique. Furthermore, the finite-time stability of the system is proved by employing the Bhat and Bernstein theorem. As a result, an adaptive finite-time tracking control scheme for the output-constrained nonlinear systems with non-strict-feedback structure is proposed by applying RBF NNs, BLF, finite-time stability theory, and adaptive backstepping technique. It is demonstrated the finite-time stability of the system, the prescribed convergence of the system output and tracking error, the boundedness of adaptive parameters and state variables. Finally, a simulation example is implemented to illustrate the effectiveness of the presented neural control scheme.  相似文献   

12.
    
The finite-time tracking control problem with the output-constraint property of robotic manipulators subjected to system uncertainties is addressed. Specifically, the radial basis function neural network is employed to compensate for system uncertainties. The finite-time stability theorem is used for the backstepping design process, by which the limit of the settling time is set. A funnel boundary is used to limit the output overshoot. The proposed controller guarantees that all the signals are semi-globally practically finite-time bounded, while the tracking errors are enveloped by the funnel boundary. The performance of the proposed control method is illustrated by a numerical simulation of a 3-DOF manipulator. It is shown that the tracking errors are bounded by prescribed funnel boundaries. In the meantime, the manipulator is stabilized within a finite period of time.  相似文献   

13.
电力系统混沌振荡的自适应   总被引:4,自引:2,他引:2  
电力系统在周期性负荷扰动的作用下会发生混沌振荡,甚至失去稳定。为抑制这种混沌振荡,利用Bs(Backstepping)控制法设计了在周期性负荷扰动幅值已知情况下的控制器;对扰动幅值未知的情况,设计了自适应Bs控制器,并利用Lyapunov稳定性理论证明了含该控制器的闭环系统可以保持渐近稳定,即能回到初始平衡点上。数值仿真也表明了该控制器的控制效果。  相似文献   

14.
采用模糊神经网络作为非线性逼近器,针对一类一阶非线性多入多出系统,提出了一种具有扰动抑制的鲁棒自适应控制方法,给出了高阶多入多出系统具有扰动抑制的自适应后推(backstepping)设计方法。在鲁棒项合理简化的情况下,给出了系统Lyapunov意义下的稳定性证明,简略分析了各设计参数的物理意义及其对系统性能的影响。理论分析和仿真实验均显示,本方法可以保证系统的全局渐近稳定性,且若选取恰当的设计参数可保证系统对输入信号的跟踪达到任意精度;由于鲁棒项的引入可使系统的设计更具灵活性。  相似文献   

15.
非线性液位系统的稳定自适应模糊控制研究   总被引:1,自引:0,他引:1  
针对工业过程中液位系统的时变、非线性特性,提出一种基于变论域模糊控制理论和Lyapunov稳定性理论的稳定自适应模糊控制方法.该方法运用了稳定的变论域自适应律,无需进行系统的模糊辨识,其改进了的控制补偿器具有更易于工程整定的特点.仿真结果验证了该控制方案的有效性.  相似文献   

16.
    
The problem of adaptive fuzzy fixed-time tracking control based on a category of nonlinear systems with unmodeled dynamics and dynamic disturbances is investigated in this article. By introducing the novel fixed-time dynamic signal, the unmodeled dynamics can be disposed of. On the basis of the fuzzy logic systems (FLSs) and adaptive backstepping technology, the disposing difficulty of the unknown nonlinear portions is reduced. Then, all signals in the closed-loop system are ensured to be bounded under the fixed-time Lyapunov stability theory. Simultaneously, the tracking error converges to a small neighborhood of the origin. Eventually, simulation consequences reveal the validity of the presented control method.  相似文献   

17.
    
In this paper, an observer-based adaptive neural output-feedback control scheme is developed for a class of nonlinear stochastic nonstrict-feedback systems with input saturation in finite-time interval. The mean value theorem and the property of the smooth function are applied to cope with the difficulties caused by the existence of input saturation. According to the universal approximation capability of the radial basis function neural network, it will be utilized to compensate the unknown nonlinear functions. Based on the state observer, the finite-time Lyapunov stability theorem, we propose an adaptive neural output-feedback control scheme for nonlinear stochastic systems in nonstrict-feedback form. The developed controller guarantees that the system output signal can track the given reference signal trajectory, and all closed-loop signals are semi-globally finite-time stability in probability. The observer errors and the tracking error can converge to a small neighborhood of the origin. Finally, simulation results demonstrate the effectiveness of the developed control scheme.  相似文献   

18.
为了解决自储能多端背靠背柔性直流系统的协调控制与电压稳定问题,提出了一种改进的电压裕度控制策略。首先建立了系统的数学模型,然后针对3种典型的运行场景设计了协调工作机制及其控制方式。基于Lyapunov稳定性理论设计了自适应指令滤波反推电压控制器,解决了系统控制方式切换导致的功率振荡与电压波动问题,改善了系统的稳定性和动态响应性。最后分别对3种典型的运行场景进行仿真分析,验证了所提控制策略和方法的有效性。  相似文献   

19.
    
This paper studies an observer‐based adaptive fuzzy control problem for stochastic nonlinear systems in nonstrict‐feedback form. The unknown backlash‐like hysteresis is considered in the systems. In the design process, the unknown nonlinearities and unavailable state variables are tackled by introducing the fuzzy logic systems and constructing a fuzzy observer, respectively. By using adaptive backstepping technique with dynamic surface control technique, an adaptive fuzzy control algorithm is developed. For the closed‐loop system, the proposed controller can guarantee all the signals are 4‐moment semiglobally uniformly ultimately bounded. Finally, simulation results further show the effectiveness of the presented control scheme.  相似文献   

20.
针对高精度的伺服系统,考虑永磁同步电动机实际运行过程中,电机的定子电阻、粘滞磨擦系数及负载转矩的变化,必然影响到系统的伺服精度。因此,提出了自适应与反推控制相结合的控制策略,通过推导,它不但能够实现永磁同步电动机系统的完全解耦,并且能够有效抑制系统参数变化对系统速度跟踪伺服性能的影响,使系统具有很强的鲁棒性。通过仿真,验证了自适应反推控制策略的有效性和可行性。  相似文献   

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