单输入网络化控制系统的时延补偿滑模控制

针对网络化控制系统中存在的网络诱导时延问题,提出了一种离散滑模控制方法。基于一类线性时不变被控对象的单输入网络化控制系统离散模型,构造了具有时延补偿的滑模面。通过系统状态预估及对状态运动的分析,设计了可以完全消除系统抖振的滑模控制器。李亚普诺夫方法证明了该控制器能使系统状态在不产生抖振的前提下收敛于滑模面,并保证系统的渐近稳定,同时不要求网络诱导时延小于一个采样周期。以位置伺服系统为对象的仿真实例验证了该设计方法的有效性。     

Sliding mode H∞ control for a class of uncertain nonlinear state-delayed systems

A new proportional-integral (PI) sliding surface is designed for a class of uncertain nonlinear state-delayed systems. Based on this, an adaptive sliding mode controller (ASMC) is synthesized, which guarantees the occurrence of sliding mode even when the system is undergoing parameter uncertainties and external disturbance. The resulting sliding mode has the same order as the original system, so that it becomes easy to solve the H∞ control problem by designing a memoryless H∞ state feedback controller. A delay-dependent sufficient condition is proposed in terms of linear matrix inequalities (LMIs), which guarantees the sliding mode robust asymptotically stable and has a noise attenuation level γ in an H∞ sense. The admissible state feedback controller can be found by solving a sequential minimization problem subject to LMI constraints by applying the cone complementary linearization method. This design scheme combines the strong robustness of the sliding mode control with the H∞ norm performance. A numerical example is given to illustrate the effectiveness of the proposed scheme.     

多输入离散不确定时滞系统变结构控制设计

研究了多输入离散不确定时滞系统的变结构控制问题。首先对原离散时滞不确定系统进行了化简,将其归结为一个无时滞的不确定离散系统形式;在此基础上提出了一种新的变结构控制设计方法和控制律算法,并给出了动态性能比较。对于不确定性为慢变的情况,该算法能使空间任意点出发的运动,都在有限时间内到达滑动模态的设定邻域,渐近稳定的到达到原点,且抖振以指数速率衰减到零。仿真结果表明了方法的有效性。     

分散自适应模糊滑模控制器与车辆跟随控制

针对一类不确定非线性大系统提出了一种新的组合型自适应分散模糊滑模控制算法.借助模糊逻辑系统与滑模方法设计的控制器加权组合了间接与直接自适应两种模糊控制器,可以同时融合被控对象知识与控制知识两种模糊信息来提高自适应效果.在一类大系统框架下基于统一的格式提出了间接与直接自适应模糊控制设计方案,并进一步消除了现有各种相关控制算法的缺陷.闭环大系统被证明是一致渐近稳定的.该算法应用于自动公路系统车辆的跟随控制,仿真结果表明提出的组合型自适应模糊控制系统比通常间接或直接自适应模糊控制系统具有更好的跟踪性能.     

Sliding mode H∞ control for a class of uncertain nonlinear state-delayed systems

A new proportional-integral (PI) sliding surface is designed for a class of uncertain nonlinear state-delayed systems. Based on this, an adaptive sliding mode controller (ASMC) is synthesized, which guarantees the occurrence of sliding mode even when the system is undergoing parameter uncertainties and external disturbance. The resulting sliding mode has the same order as the original system, so that it becomes easy to solve the H_∞ control problem by designing a memoryless H_∞ state feedback controller. A delay-dependent sufficient condition is proposed in terms of linear matrix inequalities (LMIs), which guarantees the sliding mode robust asymptotically stable and has a noise attenuation level γ in an H_∞ sense. The admissible state feedback controller can be found by solving a sequential minimization problem subject to LMI constraints by applying the cone complementary linearization method. This design scheme combines the strong robustness of the sliding mode control with the H_∞ norm performance. A numerical example is given to illustrate the effectiveness of the proposed scheme.     

基于自适应模糊快速终端滑模控制的导弹自动驾驶仪设计

针对一类多输入多输出非线性不确定系统,提出了自适应模糊快速终端滑模控制方法并应用于导弹自动驾驶仪的设计。利用模糊系统具有以任意精度逼近非线性系统的能力对未知干扰和不确定性进行逼近,并通过鲁棒项提高了系统性能。基于Lyapunov方法,证明了闭环系统所有信号渐进收敛。最后利用本文提出的控制方案设计了6自由度导弹的自动驾驶仪,仿真结果表明了控制方案的有效性和鲁棒性。     

Global robust optimal sliding mode control for uncertain affine nonlinear systems

The problem of robustifying linear quadratic regulators (LQRs) for a class of uncertain affine nonlinear systems is considered. First, the exact linearization technique is used to transform an uncertain nonlinear system into a linear one and an optimal LQR is designed for the corresponding nominal system. Then, based on the integral sliding mode, a design approach to robustifying the optimal regulator is studied. As a result, the system exhibits global robustness to uncertainties and the ideal sliding mode dynamics is the same as that of the optimal LQR for the nominal system. A global robust optimal sliding mode control (GROSMC) is realized. Finally, a numerical simulation is demonstrated to show the effectiveness and superiority of the proposed algorithm compared with the conventional optimal LQR.     

Discrete sliding mode prediction control of uncertain switched systems

The robust stabilization problem for a class of uncertain discrete-time switched systems is presented. A predictive sliding mode control strategy is proposed, and a discrete-time reaching law is improved. By applying a predictive sliding surface and a reference trajectory, combining with the state feedback correction and rolling optimization method in the predictive control strategy, a predictive sliding mode controller is synthesized, which guarantees the asymptotic stability for the closed-loop systems. The designed control strategy has stronger robustness and chattering reduction property to conquer with the system uncertainties. In addition, a unique nonswitched sliding surface is designed. The reason is to avoid the repetitive jump of the trajectories of the state components of the closed-loop system between sliding surfaces because it might cause the possible instability. Finally, a numerical example is given to illustrate the effectiveness of the proposed theory.     

Integral sliding mode control of time-delay systems with mismatching uncertainties

A linear matrix inequality (LMI)-based sliding surface design method for integral sliding mode control of uncertain timedelay systems with mismatching uncertainties is proposed.The uncertain time-delay system under consideration may have mismatching norm bounded uncertainties in the state matrix as well as the input matrix.A sufficient condition for the existence of a sliding surface is given to guarantee asymptotic stability of the full order sliding mode dynamics.An LMI characterization of the sliding surface is given,together with an integral sliding mode control law guaranteeing the existence of a sliding mode from the initial time.Finally,a simulation is given to show the effectiveness of the proposed method.     

一类非线性系统的滑模控制稳态精度研究

针对一类非线性系统的线性滑模控制和Terminal滑模控制稳态精度问题,分析使用饱和函数代替滑模控制律中符号函数的线性滑模控制和Terminal滑模控制系统的稳态误差与饱和函数宽度的数值关系,得出两者的数学表达式,为协调既削弱滑模控制的颤振又保证稳态精度的滑模控制系统的饱和函数宽度的选择提供了理论依据。定量地比较线性滑模控制和Terminal滑模控制的稳态精度,得出了Terminal滑模控制比线性滑模控制有更好稳态精度的结论,通过数值仿真算例证明理论分析的正确性。     

伺服系统模糊滑模控制器的设计与仿真

将模糊逻辑控制与滑模控制相结合，给出了一种模糊滑模控制器的设计方法。并针对伺服系统具有参数变化范围大、干扰源多等特点，设计了基于模糊滑模控制的伺服系统的结构。最后将该方法用于某机器人的机械臂的控制，并在参数大范围变化、正弦扰动作用等条件下进行了仿真。仿真结果表明，模糊滑模控制能有效地削弱传统滑模控制的“抖动”现象，并且在一定条件下具有很强的鲁棒性。     

Finite-time tracking control for motor servo systems with unknown dead-zones

A finite-time tracking control scheme is proposed in this paper based on the terminal slid- ing mode principle for motor servo systems with unknown nonlinear dead-zone inputs. By using the differential mean value theorem, the dead-zone is represented as a time-varying system and thus the inverse compensation approach is avoided. Then, an indirect terminal sliding mode control （ITSMC） is developed to guarantee the finite-time convergence of the tracking error and to overcome the singu- larity problem in the traditional terminal sliding mode control. In the proposed controller design, the unknown nonlinearity of the system is approximated by a simple sigmoid neural network, and the ap- proximation error is diminished by employing a robust term. Comparative experiments on a turntable servo system are conducted to show the superior performance of the proposed method.     

一种简单的Lorenz混沌振动主动隔振方法

以消除仪器设备中破坏性混沌运动为研究目标,在分析传统控制方法基础上,结合滑模控制原理,提出了简化的滑模控制方法。并且通过滑模控制的数学分析论证与仿真实验观察,确定了Lorenz系统状态变量的反馈变化对混沌系统有界的影响关系。运用提出的简化Lorenz系统控制变量方法所建立的消除波纹控制器,可以隔离设备中的Lorenz混沌振动,避免了仪器损坏。仿真结果证明了该方法的有效性。     

电磁悬浮平台系统的滑模控制研究

针对电磁悬浮系统中存在建模误差和外加干扰的非线性控制问题，研究了磁浮系统的滑模控制方法，设计了磁浮系统的切换超平面和基于最终滑动模态的滑模控制系统。仿真结果表明，该控制系统能有效抑制系统参数摄动引起的扰动和持续的外激力干扰，增强了系统的鲁棒性。     

严格反馈型随机非线性系统输出反馈滑模控制

研究了一类带有不确定性参数的严格反馈型随机非线性系统的输出反馈镇定问题,主要是采用变结构滑模控制方法(SMC)来设计镇定控制器。首先根据系统的结构和输出状态构造了随机非线性状态观测器,并针对结构参数的不确定性,采用梯度自适应调节律,然后基于系统的观测状态选择滑动模切换流形,给出了不含噪声激励的变结构控制律,并证明滑动模的可达性和闭环系统滑模运动的稳定性,最后讨论了滑模控制的抖振抑制问题。通过系统仿真,与其它鲁棒控制方法进行比较,证明了本方法不仅能够有效地镇定该类随机非线性系统,并且具有一些更好的控制性能。     

一类不确定时滞系统的滑模控制

考虑了一类同时存在状态不确定性和控制不确定性的时滞系统的滑模控制问题,通过采用李亚普诺夫方法和线性矩阵不等式(LMI)技术,给出了闭环系统渐近稳定的充分条件,而且滑模控制律和滑模面的设计可以利用线性矩阵不等式的解得到,证明了该滑模控制律能保证状态轨迹被驱动到指定的切换面上。仿真实验表明了算法的有效性。     

一类非线性系统的动态面二阶滑模控制

针对一类具有非匹配不确定的严格反馈非线性系统,基于动态面控制和二阶滑模控制设计方法,进行一种新颖的状态反馈控制器设计,实现了不确定系统任意小的跟踪误差。动态面控制类似于反演设计,但其包含一系列低通滤波器;低通滤波器允许控制对象数学模型不可微,这样就避免了反演设计所存在的"膨胀项",减少了计算量,易于实现。同时,由于引入二阶滑模控制,消除了传统滑模控制(一阶滑模控制)存在的抖振现象,既增强了控制系统的鲁棒性,又提高了系统的控制精度。     

Neural network based adaptive sliding mode control of uncertain nonlinear systems

The purpose of this paper is the design of neural network-based adaptive sliding mode controller for uncertain unknown nonlinear systems. A special architecture adaptive neural network, with hyperbolic tangent activation functions, is used to emulate the equivalent and switching control terms of the classic sliding mode control (SMC). Lyapunov stability theory is used to guarantee a uniform ultimate boundedness property for the tracking error, as well as of all other signals in the closed loop. In addition to keeping the stability and robustness properties of the SMC, the neural network-based adaptive sliding mode controller exhibits perfect rejection of faults arising during the system operating. Simulation studies are used to illustrate and clarify the theoretical results.     

Decentralized direct adaptive neural network control for a class of interconnected systems

1 .INTRODUCTIONA number of interconnected systems found in theworld, such as electric power systems ,industrymanipulators and computer networks , are oftencomposed of a set of subsystems . A centralizedcontrol strategy for the requirement of a large a-mount of information exchange between the sub-systems . A decentralized control method, devel-oped based only on local measurements ,is oftenpreferable . At present ,there have been many re-search results for adaptive control of interconnec-…     

基于NDO的飞行模拟转台伺服系统跟踪控制

针对飞行模拟转台伺服系统跟踪控制问题,提出了一种基于非线性干扰观测器(nonlinear disturbance observer, NDO)的反推全局滑模控制方案。该方案利用NDO观测系统的参数不确定性及非线性摩擦干扰,通过选择适当的设计参数使观测误差指数收敛,进而对引入NDO的系统采用反推全局滑模设计控制器,控制律的设计保证了闭环系统的稳定性。仿真结果表明,所提控制方案能够有效克服参数不确定性及非线性摩擦干扰的影响,实现了转角位置的精确跟踪,并且有效去除了控制抖振。