Direct adaptive control for nonlinear uncertain system based on control Lyapunov function method

1 .INTRODUCTIONIn many applications , dynamics of the plant arepartially known,and esti mation is the key in de-signing a successful control . Adaptive control ,re-presents the means of achieving online esti mation,has been the focus of research in recent years .Classes of stabilizable uncertain systems have beenfound,and several adaptive control design proce-dures have been proposed[1 ~4].The purpose of this paper is to develop newsolutions tothe adaptive stabilization problemfor aclass …     

多回路控制系统的标准系数设计法及其应用研究

对于多回路控制系统,采用标准系数法,将使控制系统设计的工作量大为简化,且比较直观。给出三种不同模型的标准系数法,并结合PID控制、伺服系统和飞行控制的多回路控制系统的综合进行应用研究。结果证明,用标准系数法设计方便,且能较确切地给出系统的过渡时间和超调量。     

Ant colony optimization algorithm and its application to Neuro-Fuzzy controller design

An adaptive ant colony algorithm is proposed based on dynamically adjusting the strategy of updating trail information.The algorithm can keep good balance between accelerating convergence and averting precocity and stagnation.The results of function optimization show that the algorithm has good searching ability and high convergence speed.The algorithm is employed to design a neuro-fuzzy controller for real-time control of an inverted pendulum.In order to avoid the combinatorial explosion of fuzzy.rules due to multivariable inputs,a state variable synthesis scheme is emploved to reduce the number of fuzzy rules greatly.The simulation results show that the designed controller can control the inverted pendulum successfully.     

Equivalent sample theory of networked control systems and its application

The equivalent sample theory and its application in analysis of networked control system （NCS） are presented. After analyzing NCS＇s scheduling in master-slave mode, the characteristics of time delay and sample are summarized. Looking on master station visiting the slave station as a special sample process, the theory of equivalent sample is presented. And based on it, the stability of a kind of NCS is analyzed. The criterion to determine the upper bound of transmission delay is introduced, which guarantees the stability. Finally, an example with simulation shows the availability and usability of this analysis method.     

基于控制Lyapunov函数新性质的逆最优控制

利用控制Lyapunov函数的新特性,对非线性仿射系统进行了逆最优控制器的设计,进一步改进了基于控制Lyapunov函数的控制器的性能,并且该控制器对于一定范围的输入不确定性具有鲁棒性。将结论用于陈氏混沌系统不稳定平衡点的渐近稳定控制律的设计中,理论分析与仿真结果证明了该方法的有效性与实用性。     

基于控制Lyapunov函数的鲁棒自适应控制器设计

研究一类含有系统扰动,并且状态项与控制项中同时含有未知参数的非线性系统的反馈稳定问题。利用鲁棒控制Lyapunov函数方法及参数映射技术,讨论了当系统存在I型与II型自适应鲁棒控制Lyapunov函数(ARCLF)时,系统的自适应控制问题,并针对两种情况分别进行了控制器的设计。通过算例验证了所提方法的可行性。     

Improved hybrid position/force controller design of a flexible robot manipulator using a sliding observer

An improved hybrid position/force controller design of a flexible robot manipulator is presented using a sliding observer. The friction between the end effector and the environment is considered and compensated. For systematic reasons the controller is designed taking into consideration the rigid link subsystems and the flexible joints. The proposed control system satisfies the stability of the two subsystems and copes with the uncertainty of robot dynamics. A sliding observer is designed to estimate the time derivative of the torque applied as input to the rigid part of the robot. For the stability of the observer, it is assumed that the uncertainty of the observed system is bounded. A MRAC algorithm is used for the estimation of the friction forces at the contact point between the end effector and the environment. Finally simulation and experimental results are given, to demonstrate the effectiveness of the proposed controller.     

智能决策系统及其在飞控系统设计中的应用

为使飞控系统的设计更加省时省力,将智能决策支持系统引入到飞控系统中。通过智能决策系统来管理飞机的数据库、模型库、控制方法等,并在知识库中应用智能算法来决策飞机的最优控制规律。在智能决策算法的开发中,采用基于踏脚石迁移模型的分布式遗传算法,将种群划分为若干子群,各子群并行地进行遗传进化,并通过迁移算子进行各子群的信息互换;在编码过程中,采用伪码与实码相互转换的编码方式,大大减少了编码的工作量。仿真结果表明,基于踏脚石迁移模型的分布式遗传决策算法能快速并有效地应用于控制系统设计中。     

Improved filtered- adaptive inverse control and its application on nonlinear ship maneuvering

The drawbacks of common nonlinear Filtered- adaptive inverse control (AIC) method, such as the unreliability due to the change of delay time and the faultiness existing in its disturbance control loop, are discussed. Based on it, the diagram of AIC is amended to accommodate with the characteristic of nonlinear object with time delay. The corresponding Filtered- adaptive algorithm based on RTRL is presented to identify the parameters and design the controller. The simulation results on a nonlinear ship model of “The R.O.V Zeefakkel” show that compared with the previous scheme and adaptive PID control, the improved method not only keeps the same dynamic response performance, but also owns higher robustness and disturbance rejection ability, and it is suitable for the control of nonlinear objects which have higher requirement to the maneuverability under complex disturbance environment.     

双线性广义系统稳定性控制分析

利用所构造的两种广义Lyapunov函数,在广义系统容许的条件下,分别设计了双线性广义系统的稳定控制,且上面存在的2种控制具有不同的表现形式.同时,考查了控制受上下界约束时,选择适当的控制,使闭环系统全局一致渐近稳定.对单输入的双线性广义系统,探讨出闭环系统在原点附近的一个稳定域.最后,给出了一个实例说明所得到结论的正确性.     

Novel active fault-tolerant control scheme and its application to a double inverted pendulum system

On the basis of the gain-scheduled H∞ design strategy, a novel active fault-tolerant control scheme is proposed. Under the assumption that the effects of faults on the state-space matrices of systems can be of affine parameter dependence, a reconfigurable robust H∞ linear parameter varying controller is developed. The designed controller is a function of the fault effect factors that can be derived online by using a well-trained neural network. To demonstrate the effectiveness of the proposed method, a double inverted pendulum system, with a fault in the motor tachometer loop, is considered.     

航天器姿态的神经网络动态逆控制

针对航天器姿态系统,提出了一种基于自适应神经网络动态逆的控制算法。该算法针对滚转、俯仰和偏航三个姿态子系统,设计了两组神经网络:第一组是BP网络,用来逼近三个姿态通道的非线性项,可获得姿态逆模型;第二组是非线性自适应神经网络,用于在线实时地补偿逆模型存在的误差和外加干扰。详细分析了非线性自适应神经网络的拓扑结构、学习规则和调整算法。给出了应用该算法的具体实例,通过仿真实验证明该算法的有效性。     

直线不稳定船舶航迹控制的稳定性研究

针对直线不稳定船舶的全局直线航迹控制,提出了一类航迹非线性状态反馈控制算法。采用Lya-punov直接法分析系统的稳定性,得到了保证闭环控制系统全局渐近稳定的充分条件,从而解决了直线不稳定船舶航迹闭环控制系统全局稳定性的判定问题。数值仿真和模拟试验结果验证了该充分条件的正确性。     

Improved filtered-ε adaptive inverse control and its application on nonlinear ship maneuvering

The drawbacks of common nonlinear Filtered-adaptive inverse control (AIC) method, such as the unreliability due to the change of delay time and the faultiness existing in its disturbance control loop, are discussed. Based on it, the diagram of AIC is amended to accommodate with the characteristic of nonlinear object with time delay. The corresponding Filtered-adaptive algorithm based on RTRL is presented to identify the parameters and design the controller. The simulation results on a nonlinear ship model of "The R.O.V Zeefakkel" show that compared with the previous scheme and adaptive PID control, the improved method not only keeps the same dynamic response performance, but also owns higher robustness and disturbance rejection ability, and it is suitable for the control of nonlinear objects which have higher requirement to the maneuverability under complex disturbance environment.     

多智能体系统的有限时间跟踪控制

基于领导-跟随者模型研究了多智能体系统的有限时间跟踪控制问题。针对领导者状态是时变的情况,提出了一类非线性有限时间跟踪控制算法,在固定网络拓扑结构下,利用Lyapunov有限时间稳定性理论和矩阵理论分析,得到了该算法使得系统中跟随者状态在有限时间内与领导者状态达到一致的充分条件;在切换网络拓扑结构下,提出了一类有限时间跟踪控制算法,在领导者的状态是时不变的情况下,给出了该算法使得系统实现有限时间跟踪控制的充分条件。仿真实例验证了所提出两类算法的有效性。     

混沌系统的一种新型模糊控制方法

基于T-S模糊动态模型,针对气象学中的Lorenz混沌系统设计出一种新型的模糊控制器和模糊观测器,均采用分段Lyapunov函数法进行设计,即对每一个子系统选一个Lyapunov函数,系统总的Lyapunov函数为各个子系统的加权和。避免了并行分配补偿法(PDC)中求解公共正定矩阵P的困难,进一步减少了设计中的保守性,扩大了解的范围。并就其稳定性问题进行了研究。得出了系统全局渐近稳定的条件。模糊观测器的设计解决了系统状态不能直接测量的问题。通过对Lorenz混沌系统的仿真,证明了该方法的有效性。该方案也适合其他类型的非线性系统,有实际应用价值。     

基于鲁棒控制Lyapunov函数的非线性自适应跟踪

研究了一类带有未知参数以及扰动的多输入非线性系统的自适应跟踪问题，利用控制Lyapunov方法设计出一种自适应控制器。该控制器对系统的参数和状态的不确定性具有鲁棒性，并且能保证系统闭环全局稳定。仿真结果表明，该控制方案具有良好的跟踪性能、鲁棒性及参数辨识能力。     

Convergence and stability of the Newton-Like algorithm with estimation error in optimization flow control

The Newton-Like algorithm with price estimation error in optimization flow control in network is analyzed.The estimation error is treated as inexactness of the gradient and the inexact descent direction is analyzed.Based on the optimization theory,a sufficient condition for convergence of this algorithm with bounded price estimation error is obtained.Furthermore,even when this sufficient condition doesn't hold,this algorithm can also converge,provided a modified step size,and an attraction region is obtained.Based on Lasalle's invariance principle applied to a suitable Lyapunov function,the dynamic system described by this algorithm is proved to be global stability if the error is zero.And the Newton-Like algorithm with bounded price estimation error is also globally stable if the error satisfies the sufficient condition for convergence.All trajectories ultimately converge to the equilibrium point.     

经济混沌模型中一种改进的反馈控制方法

就经济系统中的一类多参数混沌模型，应用非线性动力学理论，在OGY方法的基础上，对反馈控制方法进行了改进，提出了基于预测的反馈控制方法，该方法成功地进行了多参数混沌控制，并通过两例具体的经济混沌模型，对所提出的方法进行验证。     

考虑输入输出受限的无人机自适应滑模容错控制

针对存在执行器故障、控制输入饱和与状态约束的无人机(unmanned aerial vehicle, UAV)姿态控制系统,提出一种新的基于反步法的具有有限时间收敛的自适应滑模姿态容错控制方法。首先,为了抑制执行器故障以及外部干扰的影响,采用自适应和干扰观测器技术,实现对干扰的双重抑制。然后,设计动态辅助系统与障碍Lyapunov函数,证明在输入饱和与状态约束的条件下,闭环姿态控制系统可以在有限时间内稳定,且系统中所有信号最终是有界的。最后,对于小型无人系统的姿态跟踪问题进行性能仿真与对比仿真研究。仿真结果表明,所提出的容错控制方法能够保证在执行机构发生故障时控制系统的有效性,并且该方法具有良好的性能。