An output feedback sliding mode control strategy for MIMO systems of arbitrary relative degree

This paper develops an output feedback sliding mode controller for multi‐input multi‐output (MIMO) systems of any relative degree. A minimal set of outputs and output derivatives are identified to determine an augmented system which is relative degree 1, and a robust sliding mode differentiator is presented as the means to construct the extended output signal. It is shown that the transmission zeroes of the original plant appear directly in the reduced order sliding mode dynamics relating to the augmented system. A super twisting control algorithm is shown to provide robust control performance. Simulation results for a rationalized helicopter model taken from the literature are used to demonstrate the attraction of the approach. Copyright © 2010 John Wiley & Sons, Ltd.     

基于快速输出采样反馈的网络控制系统滑模控制

针对网络控制系统的网络诱导时延问题,提出了一种新的滑模控制方法。通过快速采样被控对象输出,建立了具有线性时不变被控对象的网络控制系统的离散模型。在此基础上,用极点配置法给出了滑模切换面参数,设计了输出反馈离散滑模控制器。仿真结果验证了该控制方法的有效性。     

SLIDING MODE OUTPUT TRACKING WITH APPLICATION TO A MULTIVARIABLE HIGH TEMPERATURE FURNACE PROBLEM

The paper describes a theoretical framework for the design of a robust multivariable output tracking controller using sliding mode concepts. The approach assumes that only measured outputs are available and uses a sliding mode observer to reconstruct estimates of the internal system states for use in a full information sliding mode control law. This scheme is applied to a control problem associated with high temperature furnaces. The paper describes the synthesis of the proposed control scheme from design through to implementation on an industrial test facility. © 1997 by John Wiley & Sons, Ltd.     

Output‐feedback tracking in causal nonminimum‐phase nonlinear systems using higher‐order sliding modes

Asymptotic output‐feedback tracking in a class of causal nonminimum phase uncertain nonlinear systems is addressed via sliding mode techniques. Sliding mode control is proposed for robust stabilization of the output tracking error in the presence of a bounded disturbance. The output reference profile and the unknown input/disturbance are supposed to be described by unknown linear exogenous systems of a given order. Local asymptotic stability of the output tracking error dynamics along with the boundedness of the internal states are proven. The unstable internal states are estimated asymptotically via the proposed multistage observer that is based on the method of extended system center. A higher‐order sliding mode observer/differentiator is used for the exact estimation of the input–output states in a finite time. The bounded disturbance is reconstructed asymptotically. A numerical example illustrates the efficiency of the proposed output‐feedback tracking approach developed for causal nonminimum phase nonlinear systems. Copyright © 2009 John Wiley & Sons, Ltd.     

Output feedback sliding mode control for a linear multi-compartment lung mechanics system

In this paper, we develop a sliding mode control architecture to control lung volume and minute ventilation in the presence of modelling system uncertainties. Since the applied input pressure to the lungs is, in general, nonnegative and cannot be arbitrarily large, as not to damage the lungs, a sliding mode control with bounded nonnegative control inputs is proposed. The controller only uses output information (i.e., the total volume of the lungs) and automatically adjusts the applied input pressure so that the system is able to track a given reference signal in the presence of parameter uncertainty (i.e., modelling uncertainty of the lung resistances and lung compliances) and system disturbances. Controllers for both matched and unmatched uncertainties are presented. Specifically, a Lyapunov-based approach is presented for the stability analysis of the system and the proposed control framework is applied to a two-compartment lung model to show the efficacy of the proposed control method.     

Discrete time output feedback sliding mode tracking control for systems with uncertainties

This paper describes a method for designing discrete time static output feedback sliding mode tracking controllers for uncertain systems that are not necessarily minimum phase or of relative degree one. In this work, a procedure for realizing discrete time controllers via a particular set of extended outputs is presented for systems with uncertainties. The conditions for existence of a sliding manifold guaranteeing a stable sliding motion are given. A procedure to synthesize a control law that minimizes the effect of the disturbance on the sliding mode dynamics and the augmented outputs is given. The proposed control law is then applied to a benchmark aircraft problem taken from the literature that represents the lateral dynamics of a F‐14 aircraft under powered approach. Copyright © 2013 John Wiley & Sons, Ltd.     

DYNAMICAL ADAPTIVE SLIDING MODE OUTPUT TRACKING CONTROL OF A CLASS OF NONLINEAR SYSTEMS

An alternative adaptive scheme to achieve output tracking for a class of minimum-phase dynamically input–output linearizable nonlinear systems with parametric uncertainties is considered. The proposed approach is based upon a combination of the adaptive backstepping design method and a sliding mode control (SMC) scheme to design dynamical adaptive sliding mode controllers and provide robust output tracking even in the presence of unknown disturbances. The validity of the proposed approach, regarding tracking objectives and robustness with respect to bounded stochastic perturbation inputs, is tested through digital computer simulations. © 1997 by John Wiley & Sons, Ltd.     

Dynamic output feedback integral sliding mode control design for uncertain systems

This paper addresses the problem of designing a dynamic output feedback sliding mode control algorithm for linear MIMO systems with mismatched parameter uncertainties along with disturbances and matched nonlinear perturbations. Once the system is in the sliding mode, the proposed output‐dependent integral sliding surface can robustly stabilize the closed‐loop system and obtain the desired system performance. Two types of mismatched disturbances are considered and their effects on the sliding mode are explored. By introducing an additional dynamics into the controller design, the developed control law can guarantee that the system globally reaches and is maintained on the sliding surface in finite time. Finally, the feasibility of the proposed method is illustrated by numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.     

Observation and output adaptive tracking for a class of nonlinear non-minimum phase systems

ABSTRACT

In this paper, the output tracking problem for a class of systems with unstable zero dynamics is addressed. The state is assumed not measurable. The output of the dynamical system to be controlled has to track a signal, which is the sum of a known number of sinusoids with unknown frequencies, amplitudes and phases. The non-minimum phase nature of the considered systems prevents the direct tracking by standard sliding mode methods, which are known to generate unstable behaviours of the internal dynamics. The proposed method relies on the availability of a flat output and its time derivatives which are functions of the unavailable state; therefore, a nonlinear observer is needed. Due to the uncertainty in the frequencies and in the parameters defining the relationship between the output of the system and the flat states, adaptive indirect methods are applied.     

Output feedback variable structure control for a class of uncertain switched systems

This paper considers the output feedback variable structure control problem for a class of uncertain switched systems. A single sliding surface is constructed using only output information. Robust stability of the sliding motion restricted to the sliding surface is achieved and complete invariance to the matched and the mismatched uncertainties is guaranteed via a hysteresis switching law based on a reduced order observer. Output feedback variable structure controllers are given to guarantee that the redefined sliding surface is reached in finite time. A numerical example illustrates the effectiveness of the proposed design method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

非线性相似组合系统的鲁棒输出跟踪控制*

研究一类具有相似结构的非线性不确定组合系统的分散输出跟踪控制问题,利用的相似结构,提出一种设计具有相似结构的分散滑模控制器的方法,所设计的控制器,对于所有允许的不确定性,均使系统输出渐近跟踪所给定的参考输出。     

Global stabilisation for a class of nonlinear time-delay systems based on dynamical output feedback sliding mode control

In this article, global stabilisation for a class of nonlinear time-varying delay systems with mismatched uncertainty is considered. The bound on the uncertainty is nonlinear and involves time-delay. For this system, a dynamical compensator is first designed. A delay free sliding surface in the augmented space formed by the system output and the compensator state variables is proposed. The stability of the sliding mode dynamics, which include the time-delay effects, are analysed using the Lyapunov–Razumikhin approach. Then, a delay dependent sliding mode control is proposed such that the system can be driven to the sliding surface in finite time and maintain a sliding motion on it thereafter. Finally, a simulation is presented to illustrate the effectiveness of the obtained results.     

Adaptive sliding mode control for a class of uncertain discrete-time systems using multi-rate output measurement

This article is concerned with the design of an adaptive sliding mode control (SMC) for a class of uncertain discrete-time systems using the multi-rate output measurement. The states of the discrete-time systems are assumed to be taken in the multi-rate output measurement by the contamination with measurement noise. The uncertainties are assumed not to satisfy the matching condition, and are expressed in a parameterised form. A least squares estimator (LSE) to take the estimates for the un-measurable states and the uncertainties is designed in a batch form by using the noisy multi-rate output measurement. The proposed adaptive SMC is designed by using the sliding surface expressed as the linear state function and the estimates obtained from the LSE. It is proved that the estimation errors converge to zero as time tends to infinite, and the states of the system are bounded under the action of the proposed adaptive SMC. The effectiveness of the proposed method is indicated through the simulation experiment in a simple system.     

具有输出/全状态约束的固定时间滑模控制

本文主要解决具有约束的二阶系统的固定时间跟踪控制问题,分别讨论了具有输出约束与具有全状态约束的控制算法设计.首先,为解决输出约束下的固定时间控制问题,本文构建了具有输出约束的新型终端滑模变量,并设计了具有扰动抑制能力的固定时间滑模控制律,保证系统输出始终满足约束条件,同时跟踪误差在固定时间内收敛到原点的充分小的邻域内.进一步,为了处理具有全状态约束的控制问题,本文构建了具有全状态约束的终端滑模变量并设计了相应的固定时间滑模控制律.鉴于系统控制律的不连续性,文章采用非光滑分析及Lyapunov稳定性理论证明了闭环控制系统的稳定性.最后,在数值仿真中,将本文提出的方法与传统固定时间滑模方法进行对比,验证了所建立算法的有效性.     

无抖振离散滑模输出反馈控制方法及仿真研究

针对离散时间系统,提出了一种基于多速率采样输出反馈和幂次函数趋近律的离散滑模控制方法;理论分析表明,通过引入幂次函数可消除离散滑模控制系统的抖振;采用多速率采样技术,运用不同采样速率下的系统输出值表示系统状态,实现了仅用系统输入输出采样值完成离散滑模控制器的设计,减轻了控制系统设计的复杂性;仿真结果表明,控制器的输出、切换函数、系统的输出均不存在抖振现象,而且控制系统表现出了良好的动态特性。     

非线性组合系统的鲁棒分散输出跟踪

研究一类具有结构不确定性的非线性相似组合系统的鲁棒分散输出跟踪控制问题。对于系统中的非匹配不确定性,利用参数摄动法设计出分散滑模控制器,使得跟踪误差收敛到零点的小邻域内。该邻域的半径可表示为设计参数的K类函数,并使系统的状态保持有界。仿真例子进一步验证了所提出设计方法的有效性。     

Output feedback relay control in the second‐order sliding mode context with application to an electropneumatic system

In this paper, a new second‐order sliding mode output feedback control law is proposed. It amounts to approach the dynamic performance of the twisting algorithm, but the main advantage of this new control method is that it requires only the information of the sliding variable, and not its derivative. A gain adaptation law is also developed for this new control law. Then this control strategy is applied to the position control of an electropneumatic system, and its performance is compared with other two very recent adaptive second‐order sliding mode control laws. Copyright © 2016 John Wiley & Sons, Ltd.     

动态滑模控制及其在移动机器人输出跟踪中的应用

针对轮式移动机器人的输出跟踪问题,提出一种动态滑模控制方法,首先给出机器人的动力学简化模型,然后将其分解成两个低阶子系统,并给出其输出跟踪的动态滑模控制器设计方法,仿真试验表明该方法能明显地削弱滑模控制系统的抖振。     

A multitask sliding mode control for mismatched uncertain large-scale systems

A new sliding mode control (SMC) approach, output variables only, single phase only and chattering phenomenon free, is presented for a class of mismatched uncertain large-scale systems. For a new multitask SMC, it is not required that the system states are available. Moreover, the sliding function in this study just depends on output variables. Using an exponential type sliding surface, the system states are always in the sliding mode at the beginning time t = 0. Using a newly appropriate linear matrix inequality stability conditions by the Lyapunov method are derived such that each subsystem in the new sliding mode is completely invariant to matched uncertainties. As a result, robustness of the mismatched uncertain large-scale systems can be assured throughout an entire response of the system starting from the initial time t = 0. In every subsystem, a scheme of decentralised control using only output states is proposed. In addition, a continuous controller is finally designed for chattering removal. Finally, a numerical example is used to demonstrate the efficacy of the proposed method.     

一类多执行机构系的滑模控制设计及其应用

针对一类具有多执行机构的非线性系统,利用滑模控制和backstepping技术,研究了输出跟踪问题.针对执行机构的不同特点,利用离散执行机构实现滑模控制中的不连续控制量,利用连续执行机构实现滑模控制中的连续控制量.然后利用backstepping技术实现连续执行机构的输出对滑模控制中的连续控制量的有限时间收敛.将提出的设计方法应用于导弹直接侧向力与气动力复合控制系统设计,并进行了仿真验证.