线性时滞系统的鲁棒故障诊断

研究了一类含有未知输入干扰和模型不确定性的时滞系统故障诊断问题。通过变换,原系统被分成两个子系统,一个子系统不受故障的影响,可以设计鲁棒观测器;另一个子系统受到故障的影响,但是它的状态可以通过测量得到。设计的观测器利用解析冗余方法能够对执行器故障和传感器故障进行诊断。仿真结果表明,算法具有良好的诊断性能。     

Robust fault detection and diagnosis for uncertain nonlinear systems

This paper considers robust fault detection and diagnosis for input uncertain nonlinear systems. It proposes a multi-objective fault detection criterion so that the fault residual is sensitive to the fault but insensitive to the uncertainty as much as possible. Then the paper solves the proposed criterion by maximizing the smallest singular value of the transformation from faults to fault detection residuals while minimizing the largest singular value of the transformation from input uncertainty to the fault detection residuals. This method is applied to an aircraft which has a fault in the left elevator or rudder. The simulation results show the proposed method can detect the control surface failures rapidly and efficiently.     

卫星姿态系统的抗干扰完整性容错控制

研究了一种线性不确定系统的完整性容错控制问题。针对卫星姿态系统中的执行机构完全失效故障,采用4个反作用飞轮结构进行姿态控制,利用Riccati方程和线性矩阵不等式组,提出一种具有抗干扰特性且对执行机构完全失效故障具有完整性的状态反馈容错控制设计方法。在此基础上进一步得出该控制器可以用于更多种故障形式的结论。最后在卫星姿态系统上对此方法进行了数学仿真,结果验证了该方法的正确性和有效性。     

Optimal deterministic disturbances rejection for singularly perturbed linear systems

1. INTRODUCTION It is well known that external disturbances exist in almost all practical systems, such as wind or ocean wave forces in active control systems for offshore structures[1], harmonic oscillations in flight control systems through wind shear[2] , and periodic disturb- ance in the disk drive[3]. In recent years, various reliable approaches with regard to the disturbance rejection and cancellation have been well documented in many literatures. Lee et al. [4] proposed the model-ba…     

Novel robust fault diagnosis method for flight control systems

A novel robust fault diagnosis scheme, which possesses fault estimate capability as well as fault diagnosis property, is proposed. The scheme is developed based on a suitable combination of the adaptive multiple model （AMM） and unknown input observer （UIO）. The main idea of the proposed scheme stems from the fact that the actuator Lock-in-Place fault is unknown （when and where the actuator gets locked are unknown）, and multiple models are used to describe different fault scenarios, then a bank of unknown input observers are designed to implement the disturbance de-coupling. According to Lyapunov theory, proof of the robustness of the newly developed scheme in the presence of faults and disturbances is derived. Numerical simulation results on an aircraft example show satisfactory performance of the proposed algorithm.     

一类非线性互联大系统的近似最优扰动抑制

研究一类受外界扰动非线性互联动态大系统的最优扰动抑制问题。根据有限时域二次型性能指标,提出了一种基于逐次逼近思想的大系统近似最优扰动抑制方法。利用该方法将由原系统得到的高阶耦合的非线性两点边值问题简化为一族解耦的线性两点边值问题序列。证明了该序列的解一致收敛于原非线性互联大系统的最优控制。通过截取最优控制序列的有限次逼近值,可以得到非线性互联大系统近似最优扰动抑制控制律。最后通过数值仿真表明了该方法的有效性。     

奇异时滞系统的鲁棒故障检测和分离观测器

讨论了一类不确定奇异时滞系统的鲁棒故障检测和分离观测器(RDO)设计问题,设计所有的观测器使得它们的冗余信号对非故障因素具有鲁棒性,并设计每个观测器使其冗余信号对一组特定的故障不敏感而对其余故障敏感。给出了RDO存在的充分条件及有效的设计算法,并讨论了故障集合不同划分的RDO设计之间的关系,最后给出一具体算例来说明该方法的有效性。     

Feedforward and feedback optimal control for linear time-varying systems with persistent disturbances

1 .INTRODUCTIONIn nature ,there are various external disturbancesaffecting the performances of systems . Many con-trol problemsinvolve designing a controller capableof stabilizing a given linear system while mini mi-zing the worst-case response to some additive dis-turbances . This problemis relevant to disturbancerejection and cancellation. One application area ofinterest is flight control through wind shear ,where disturbances arise from a modal for windshear based on harmonic oscillati…     

Research and application of hierarchical model for multiple fault diagnosis

1.INTRODUCTION Failureanalysisanddiagnosisoflarge scalesystems havereceivedconsiderableattentionduringtherecent years[1～3].Thesesystemshaveevolvedfromthepre viousonesbasedonheuristicknowledgeofsymptom faultassociationstothemorerecentonesbasedon structure,behaviorandfunctionalityofthedevice andsubsystemtobediagnosed[4].Inthecaseof complexsystem,theapplicationofmodel baseddiag nosisalgorithmsbecomescomputationallyverydiffi cultorevenintractable.Ahierarchicaldiagnosisap proachcansignificant…     

航天器姿态机动的自抗扰控制器设计

基于三阶扩张状态观测器、安排过渡过程和非线性反馈技术,设计了三通道耦合的航天器姿态机动自抗扰控制器,完成了自抗扰控制器的参数整定。从对模型的依赖程度、抗干扰性、鲁棒性和燃料消耗等四个方面对比了自抗扰控制器和PD控制器。仿真结果表明自抗扰控制器在解决存在非线性和耦合特性的航天器姿态控制问题上能够取得理想的控制效果,具有较高的控制精度和较快的系统响应。     

Actuator fault diagnosis of time-delay systems based on adaptive observer

1 .INTRODUCTIONOwingtotheincreasing demandfor highreliabilityinmany industrial processes , much attention has beenpaid to the problem of fault detection and diagnosis(FDD) in dynamic systems over the past twodecades. Fruitful results can be found in Refs .[1 ~3] .It is well known that faults in a dynamic systemcan take many forms . They can be actuator faults ,sensor faults ,unexpected abrupt changes of some pa-rameters or even unexpected structure changes[4 ,5].The purpose of detection…     

Robust bounded control for uncertain flight dynamics using disturbance observer

The robust bounded flight control scheme is developed for the uncertain longitudinal flight dynamics of the fighter with control input saturation invoking the backstepping technique. To enhance the disturbance rejection ability of the robust flight control for fighters, the sliding mode disturbance observer is designed to estimate the compounded disturbance including the unknown external disturbance and the effect of the control input saturation. Based on the backstepping technique and the compounded disturbance estimated output, the robust bounded flight control scheme is proposed for the fighter with the unknown external disturbance and the control input saturation. The closed-loop system stability under the developed robust bounded flight control scheme is rigorously proved using the Lyapunov method and the uniformly asymptotical convergences of all closed-loop signals are guaranteed. Finally, simulation results are presented to show the effectiveness of the proposed robust bounded flight control scheme for the uncertain longitudinal flight dynamics of the fighter.     

飞行器电子系统的多故障诊断算法研究

飞行器电子系统的多故障诊断问题可看作对各部件的故障概率求解的组合优化问题,在建立了系统故障诊断的概率因果模型基础上,运用遗传算法对飞行器电子设备各部件进行了故障定位。并针对遗传算法易陷入局优的缺点,提出了改进方法,将能量熵的选择加入到遗传算法的退火选择中,以充分地探索解空间,保持种群的多样性。试验结果表明,改进遗传算法能快速确定全局最优值,较好地解决了故障诊断领域中多故障关联的问题。     

基于干扰估计的BTT导弹鲁棒方差姿态控制

针对存在非线性和不确定性的倾斜转弯(bank-to-turn, BTT)导弹姿态控制问题,提出基于干扰估计的鲁棒方差控制方法。将姿态运动中非线性项和不确定项作为总干扰,采用干扰观测器进行估计,并引入控制系统进行补偿。干扰观测器的观测误差作为BTT导弹姿态运动的干扰输入,为了保证控制系统具有良好的动态和稳态性能,采用鲁棒方差控制理论设计了线性反馈控制器,将闭环极点配置在特定圆盘区域,同时将状态变量的稳态方差保持在给定的范围内。仿真结果表明,所提出的鲁棒方差姿态控制器能够保证良好的控制效果,鲁棒性强。     

Robust fault detection for a class of nonlinear network control system with communication delay

To investigate a class of nonlinear network control system, a robust fault diagnosis method is presented based on the robust state observer. To access the objective that the designed robust filter is maximally tolerant to disturbances and sensitive to fault, the robustness and stability properties of the fault diagnosis scheme are established rigorously. Using the residual vector, a fault tolerant controller is established in order to guarantee the stability of the closed-loop system, and the controller law can be obtained by solving a set of linear matrix inequalities. Then, some relevant sufficient conditions for the existence of a solution are given by applying Lyapunov stability theory. Finally, a simulation example is performed to show the effectiveness of the proposed approach.     

控制系统故障检测与诊断技术的最新进展

对故障检测与诊断(FDD)技术在控制领域的最新进展进行了综述,内容主要包括三类基本方法,即:基于解析模型的FDD、基于信号处理和基于知识的故障检测与诊断方法。重点评述了近年来发展起来的信息融合方法、多Agent方法、鲁棒故障检测、网络控制系统的故障诊断等。最后介绍了故障检测与诊断技术在控制系统中的若干应用成果,并指出尚待解决的主要问题和值得进一步研究的方向。     

高超声速飞行器自抗扰姿态控制器设计

针对高超声速飞行器无动力再入过程中具有强耦合、气动参数摄动及不确定性的非线性姿态模型,结合自抗扰控制中的扩张状态观测器(extended state observer, ESO)及非线性状态误差反馈律(nonlinear law state error feedback, NLSEF),分别设计了高超声速飞行器内环和外环自抗扰姿态控制器。将不确定性、耦合及参数摄动等干扰作为“总和干扰”利用扩张状态观测器进行估计并动态反馈补偿,再利用NLSEF抑制补偿残差。自抗扰控制器(active disturbance rejection control, ADRC)设计无需精确的飞行器被控模型,也无需精确的气动参数及摄动界限。仿真结果表明,控制系统能够克服干扰及气动参数大范围摄动的影响,在获取良好的动态品质和跟踪性能的同时,具有较强的鲁棒性。     

Robust iterative learning control for nonlinear systems with measurement disturbances

The iterative learning control (ILC) has been demon-strated to be capable of considerably improving the tracking perfor-mance of systems which are affected by the iteration-independent disturbance. However, the achievable performance is greatly degraded when iteration-dependent, stochastic disturbances are pre-sented. This paper considers the robustness of the ILC algorithm for the nonlinear system in presence of stochastic measurement disturbances. The robust convergence of the P-type ILC algorithm is firstly addressed, and then an improved ILC algorithm with a decreasing gain is proposed. Theoretical analyses show that the proposed algorithm can guarantee that the tracking error of the nonlinear system tends to zero in presence of measurement dis-turbances. The analysis is also supported by a numerical example.     

非线性系统执行器死区故障的鲁棒自适应控制

针对一类具有不对称执行器死区故障的不确定非线性系统,基于反推滑模控制原理提出了一种神经网络鲁棒自适应控制方案。通过简化死区故障模型,取消了模型倾斜度相等和边界对称条件,结合动态面控制避免了传统反推设计方法存在的计算复杂性问题。所提控制方案取消了控制方向已知的条件,消除了执行器死区故障的影响,使得系统输出趋于给定参考轨迹的一个小领域。仿真结果验证了该方法的有效性。