【作者】 李豪；

【导师】 屈剑锋；

【作者基本信息】 重庆大学 ， 控制科学与工程， 2021， 硕士

【摘要】 随着现代工业技术的飞速发展,系统的安全可靠运行是必然趋势。在大多数应用领域,故障通常是间歇的。间歇故障广泛存在于电子、机械设备和电力系统中,也经常出现在现代尖端科技领域。此外,间歇故障反复随机出现,导致很难快速、准确地诊断和分离。在间歇故障的研究成果中,大多针对特定对象的数据驱动方法都关注于系统是否发生间歇故障,无法检测其所有的出现时间和消失时间,而基于解析模型的方法可以有效解决这个问题。区间观测器作为观测器理论的有力补充,其区间计算可以避免传统的基于观测器故障诊断方法的残差评估和阈值选择步骤,为间歇故障的在线诊断提供新的思路,但目前区间观测器的协同约束和保守估计仍然是需要研究的问题。同时,对于大多数的实际系统来说,几乎不可能在完全已知参数和没有干扰噪声的情况下对系统建模。针对这些难点以及研究中存在的问题,本文工作主要包含以下内容。针对一类受未知干扰和噪声影响的不确定系统,提出一种鲁棒区间观测器设计方法。通过坐标变换保证误差动态系统的协作性,将观测器增益设计转化为Sylvester方程求解问题,避免了增益矩阵存在性的假设。然后在设计好区间观测器结构基础上,充分利用求解Sylvester方程时丰富的自由度,设计具有H_∞性能的观测器增益,从而得到更紧凑的区间估计。针对间歇故障检测难和自适应阈值选择困难的问题,基于区间观测器的上下界估计,提出一种间歇故障检测方法。使用区间观测器进行间歇故障诊断研究在本文被首次考虑。区间观测器的状态计算是在每一时刻给出的,其残差的生成不会受历史数据的影响,且区间观测器的估计值可以直接用于间歇故障检测,是一个天然的自适应阈值。其次,基于滑动时间窗和计数器设计了间歇故障、瞬态故障和永久故障的识别方案,为后续维修处理提供帮助。针对传感器间歇故障的隔离定位问题,提出一种基于多区间观测器的故障隔离方案。不仅能检测传感器间歇故障,还能对其进行定位。考虑到传感器的故障行为会导致控制器误控制,从而影响闭环反馈系统稳定性,提出一种输出反馈容错控制策略,在系统发生间歇故障时,可以重构反馈信号保证控制性能。最后,搭建直流电机控制系统DR300的Simulink模型进行实验验证。通过设计多个鲁棒区间观测器用于间歇故障的检测和隔离,并在隔离出故障后重构输出作为新的反馈,保证系统稳定运行。更多还原

【Abstract】 With the rapid development of modern industrial technology,the safe and reliable operation of the system is an inevitable trend.In most application area,faults are usually intermittent.Intermittent fault is widely present in electronic,mechanical equipment and power systems,and often appears in modern cutting-edge technology fields.In addition,intermittent fault occurs repeatedly and randomly,making it difficult to diagnose and isolate it quickly and accurately.In the research results of intermittent fault,most of the data-driven methods for specific objects focus on whether intermittent fault occurs in the system,which fail to detect all its appearance and disappearance times,while the method based on analytical model can effectively solve this problem.The interval observer,as a powerful supplement to observer theory,can avoid the residual evaluation and threshold selection steps of the traditional observer-based fault diagnosis method,and provide a new idea for the real-time diagnosis of intermittent fault.However,the cooperative constraint and conservative estimation of interval observer are still problems that need to be studied at present.At the same time,for most real systems,it is almost impossible to model a system with fully known parameters and without considering disturbance and noise.In view of these difficulties and problems existing in the research,this paper mainly includes the following contents.For a class of uncertain systems with unknown disturbance and noise,a robust interval observer design method is proposed.The coordination of the dynamic error system is guaranteed by coordinate transformation,and the design of the observer gain is transformed into a Sylvester equation solving problem,avoiding the assumption of the existence of the gain matrix.Then,based on the design of the interval observer structure,taking full advantage of the abundant degrees of freedom in solving the Sylvester equation,an interval observer gain with H_∞performance is designed,and a more compact interval estimation is obtained.In view of the difficulties in intermittent fault detection and adaptive threshold selection,an intermittent fault detection method is proposed based on the upper and lower bound estimations of interval observer.The use of interval observer to study the problem of intermittent fault diagnosis is considered for the first time in this article.The state calculation of interval observer is given at every moment,and the generation of its residuals will not be affected by historical data.The estimation value of interval observer can be directly used for intermittent fault detection,which is a natural adaptive threshold.At the same time,the identification scheme for intermittent fault,transient fault and permanent fault is designed based on sliding time window and counter,which can provide help for subsequent maintenance and treatment.Aiming at the isolation and location problem of the sensor intermittent fault,an intermittent fault isolation method based on multi-interval observers is proposed.It can not only detect sensor intermittent fault,but also locate the fault.Considering that the failure behavior of the sensor will lead to the error control of the controller,which will affect the stability of the closed-loop feedback system,an output feedback fault-tolerant control strategy is proposed.When the intermittent fault occurs,the feedback signal can be reconstructed to ensure the control performance.Finally,a Simulink model of DC motor control system DR300 is built for experimental verification.Multiple robust interval observers are designed for intermittent fault detection and isolation,and the output is reconstructed as a new feedback after the fault isolation,so as to ensure the stable operation of the system.更多还原