基于互质因子摄动的系统非脆弱鲁棒解耦控制

研究对象和控制器存在互质因子不确定性时闭环系统鲁棒稳定和非脆弱鲁棒解耦控制问题,得到了闭环系统具有鲁棒稳定性和鲁棒解耦性能的充分条件,给出了鲁棒控制器的优化设计方法.     

一类不确定时滞奇异系统的鲁棒非脆弱控制

针对不确定奇异时滞系统,研究了鲁棒非脆弱控制问题.假定不确定性范数有界,设计了基于观测器的控制器,使得闭环系统在不确定性影响下保持鲁棒稳定.仅通过求解相应线性矩阵不等式就可得到鲁棒状态反馈控制器,该控制器不仅对所有容许的系统不确定性使相应的闭环系统渐近稳定,而且满足控制器本身是非脆弱的,达到抑制干扰的效果.     

鲁棒观测器-控制器的设计*

本文讨论了多变量系统参数摄动下鲁棒观测器-控制器的设计方法,并给出了带观测器-控制器闭环系统的鲁棒稳定条件。     

一类不确定时滞奇异系统的鲁棒非脆弱控制

针对不确定奇异时滞系统，研究了鲁棒非脆弱控制问题。假定不确定性范数有界，设计了基于观测器的控制器，使得闭环系统在不确定性影响下保持鲁棒稳定。仅通过求解相应线性矩阵不等式就可得到鲁棒状态反馈控制器，该控制器不仅对所有容许的系统不确定性使相应的闭环系统渐近稳定，而且满足控制器本身是非脆弱的，达到抑制干扰的效果。     

一类不确定线性系统的鲁棒自适应控制

针对一类同时具有匹配不确定性和不匹配政治面目 确定性的线性系统,首先采用李雅普诺夫稳定性定理,结合基于矩阵不等式的鲁棒控制器设计方法和变结构控制方法,设计鲁棒控制器,使得闭环系统是二次渐近稳定的,然后,利用自适应参数估计方法,设计具有匹配不确定性范数界估计能力的鲁棒自适应控制器,保证闭环系统的一致终结有界,在此基础上,进一步考虑系统中可能的未知不确定性,分析闭环系统的鲁棒性,并得到了相应的控制器设计方法。     

一类具有范数有界的非线性不确定性时滞系统的鲁棒H∞控制器设计

研究一类具有有界范数非线性不确定性的线性时滞系统的鲁棒Ｈ∞控制，提出一种鲁棒Ｈ∞控制器的设计方法。该控制器不仅能鲁棒镇定原不确定系统，还能保证闭环系统一定的Ｈ∞性能。     

不匹配不确定线性时滞系统的鲁棒自适应控制

对一类同时具有匹配不确定性及结构确定不匹配不确定性的不确定时滞系统进行鲁棒自适应控制。首先,采用李雅谱诺夫函数方法,结合基于线性矩阵不等式的鲁棒控制器设计方法和变结构控制方法,设计鲁棒控制器,保证闭环系统的二次渐近稳定。利用自适应参数估计方法,设计具有匹配不确定性范数界估计能力的鲁棒自适应控制器,保证闭环系统的一致终结有界。结合算例,进行控制器的设计和仿真研究,验证所提出的设计方法的有效性。     

不确定离散系统的鲁棒非脆弱H∞控制

针对线性不确定离散系统,研究了鲁棒非脆弱H∞状态反馈控制器的设计问题。鲁棒性是研究被控系统模型参数摄动对闭环系统的影响,脆弱性是研究控制器参数摄动对闭环系统的影响。在系统模型和控制器同时存在不确定时,只有鲁棒非脆弱的控制器才能保证闭环系统的稳定和满足给定性能。系统的不确定项参数时变且具有线性分式形式的范数有界,控制器的增益变化也是时变且具有线性分式形式的范数有界。基于线性矩阵不等式方法,给出了具有加性和乘性控制器增益变化的鲁棒非脆弱控制器存在的充要条件。实例表明了该设计方法的有效性。     

基于输出反馈的鲁棒容错D-稳定性分析

研究线性不确定系统基于输出反馈的鲁棒容错控制问题.基于连续型执行器故障模式,利用线性矩阵不等式LMI,给出了系统基于输出反馈的鲁棒容错D-稳定的充分条件,并把控制器的设计方法归结为求解一族线性矩阵不等式组.与常规的方法相比,给出的控制器不仅保证闭环系统对执行器故障具有完整性,并且使闭环系统的极点配置在指定区域D中.通过仿真示例表明,无论执行器发生故障与否,得到的基于输出反馈的鲁棒容错控制器均保证闭环系统是D-稳定的,从而验证了所提出设计方法的有效性.     

一类具有状态及控制滞后的不确定系统的鲁棒H∞控制

本文就一类具有状态及控制滞后的不确定动态系统,研究了其鲁棒Ｈ∞控制,文中提出一种鲁棒无记忆Ｈ∞控制器的设计方法,该控制器在鲁棒镇定系统的同时,能保证闭环系统从扰动到被控输出的Ｈ∞范数小于某一给定的常数。     

A robust stabilization problem of fuzzy control systems and itsapplication to backing up control of a truck-trailer

A robust stabilization problem for fuzzy systems is discussed in accordance with the definition of stability in the sense of Lyapunov. We consider two design problems: nonrobust controller design and robust controller design. The former is a design problem for fuzzy systems with no premise parameter uncertainty. The latter is a design problem for fuzzy systems with premise parameter uncertainty. To realize two design problems, we derive four stability conditions from a basic stability condition proposed by Tanaka and Sugeno: nonrobust condition, weak nonrobust condition, robust condition, and weak robust condition. We introduce concept of robust stability for fuzzy control systems with premise parameter uncertainty from the weak robust condition. To introduce robust stability, admissible region and variation region, which correspond to stability margin in the ordinary control theory, are defined. Furthermore, we develop a control system for backing up a computer simulated truck-trailer which is nonlinear and unstable. By approximating the truck-trailer by a fuzzy system with premise parameter uncertainty and by using concept of robust stability, we design a fuzzy controller which guarantees stability of the control system under a condition. The simulation results show that the designed fuzzy controller smoothly achieves backing up control of the truck-trailer from all initial positions     

基于二次稳定的仿真转台鲁棒控制器设计

针对摩擦力矩干扰,系统参数摄动等非线性扰动环节对仿真转台控制系统的影响,提出了基于二次稳定理论的仿真转台鲁棒控制器设计思想。分析了二次稳定理论的基本原理及设计方法,给出了某型飞行仿真转台基于二次稳定的状态反馈控制器和PID鲁棒控制器设计实例。仿真结果表明,基于二次稳定理论的控制器克服了摩擦力矩干扰以及转动惯量摄动对仿真转台的影响,实现了转台转角的精确控制,动态指标优越,满足了高精度飞行仿真转台系统的鲁棒控制要求。     

一类非自衡过程预测PID控制器的设计及鲁棒稳定性的分析研究*

针对一类非自衡过程,为了提高系统的整体性能,提出了预测PID控制器的设计方法;利用Kharitonov 定理和边缘理论分析此系统在参数不确定情况下输入、输出的鲁棒稳定性,并给出了系统保持稳定的最大过程参数区间。仿真结果表明,当过程参数偏离标称值时,此预测PID控制器的设计方法能够使系统保持很好的鲁棒稳定性,是一种值得在实际工程中推广应用的新型控制器。     

Equivalence of robust stabilization and robust performance via feedback

One approach to robust control for linear plants with structured uncertainty as well as for linear parameter-varying plants (where the controller has on-line access to the varying plant parameters) is through linear-fractional-transformation models. Control issues to be addressed by controller design in this formalism include robust stability and robust performance. Here robust performance is defined as the achievement of a uniform specified L ²-gain tolerance for a disturbance-to-error map combined with robust stability. By setting the disturbance and error channels equal to zero, it is clear that any criterion for robust performance also produces a criterion for robust stability. Counter-intuitively, as a consequence of the so-called Main Loop Theorem, application of a result on robust stability to a feedback configuration with an artificial full-block uncertainty operator added in feedback connection between the error and disturbance signals produces a result on robust performance. The main result here is that this performance-to-stabilization reduction principle must be handled with care for the case of dynamic feedback compensation: casual application of this principle leads to the solution of a physically uninteresting problem, where the controller is assumed to have access to the states in the artificially-added feedback loop. Application of the principle using a known more refined dynamic-control robust stability criterion, where the user is allowed to specify controller partial-state dimensions, leads to correct robust-performance results. These latter results involve rank conditions in addition to linear matrix inequality conditions.     

鲁棒H-状态反馈控制

本文对结构参数不确定线性定常多变量系统的鲁棒Ｈ∞状态反馈设计问题进行了研究，给出了系统鲁棒稳定和干扰衰减的条件，及相应的鲁棒Ｈ∞状态反馈设计方法，并用这种方法设计了一个倒立摆平衡控制器。仿真结果表明，与ＬＱ设计方法相比，按本文所提出的设计方法得到的控制器具有鲁棒稳定能力强、闭环动态性能良好等优点。     

球形对象族的最优鲁棒镇定

本文对球形对象族系统最优鲁棒镇定问题进行了研究.利用最小范数解方法求解球形对象族的可镇定性半径.可镇定性半径是系统稳定性半径的上界,最优控制器的稳定性半径等于镇定性半径.文中给出球形对象族最优鲁棒控制器的形式,并通过示例具体说明球形对象族最优鲁棒控制器的设计方法.     

Robust hybrid predictive control of nonlinear systems

In this work, we consider nonlinear systems with input constraints and uncertain variables, and develop a robust hybrid predictive control structure that provides a safety net for the implementation of any model predictive control (MPC) formulation, designed with or without taking uncertainty into account. The key idea is to use a Lyapunov-based bounded robust controller, for which an explicit characterization of the region of robust closed-loop stability can be obtained, to provide a stability region within which any available MPC formulation can be implemented. This is achieved by devising a set of switching laws that orchestrate switching between MPC and the bounded robust controller in a way that exploits the performance of MPC whenever possible, while using the bounded controller as a fall-back controller that can be switched in at any time to maintain robust closed-loop stability in the event that the predictive controller fails to yield a control move (due, e.g., to computational difficulties in the optimization or infeasibility) or leads to instability (due, e.g., to inappropriate penalties and/or horizon length in the objective function). The implementation and efficacy of the robust hybrid predictive control structure are demonstrated through simulations using a chemical process example.     

Robust multivariable control of complex biological processes

This paper addresses advanced control of a biological nutrient removal (BNR) activated sludge process. Based on a previously validated distributed parameter model of the BNR activated sludge process, we present robust multivariable controller designs for the process, involving loop shaping of plant model, robust stability and performance analyses. Results from three design case studies showed that a multivariable controller with stability margins of 0.163, 0.492 and 1.062 measured by the normalised coprime factor, multiplicative and additive uncertainties respectively give the best results for meeting performance robustness specifications. The controller robustly stabilises effluent nutrients in the presence of uncertainties with the behaviour of phosphorus accumulating organisms as well as to effectively attenuate major disturbances introduced as step changes. This study also shows that performance of the multivariable robust controller is superior to multi-loops SISO PI controllers for regulating the BNR activated sludge process in terms of robust stability and performance and controlling the process using inlet feed flowrate is infeasible.     

冷带轧机厚控系统自适应鲁棒输出反馈动态控制器设计

冷带轧机厚控系统可被认为是一个受外界干扰的线性不确定时滞系统.本文首先设计了标称系统下的鲁棒输出反馈动态控制器,以改善闭环系统的动静态性能;其次,在系统不需要满足不确定性匹配条件的情况下,将参数和外部扰动不确定性综合考虑.应用Lyapunov稳定性理论设计了系统不确定性上界参数的自适应估计器和系统的自适应控制器,保证了闭环系统的渐近稳定性,减小了设计的保守性;两者结合实现了板带出口厚度的有效控制.最后通过一个仿真实例说明本文所提出的自适应鲁棒控制器的有效性.     

高阶时滞过程预测PID控制器设计及鲁棒稳定性分析

针对高阶加滞后对象稳定性分析的局限性,提出了预测PID控制器的设计方法,利用Kharitonov定理和边缘理论分析此系统在参数不确定情况下输入、输出的鲁棒稳定性,并给出了系统保持稳定的最大过程参数区间。仿真结果表明,当过程参数偏离标称值时,此类预测PID控制器的设计方法能够使系统保持很好的控制性能和鲁棒稳定性能。是一种值得在实际工程中推广应用的新型控制器。