Dynamic train dwell time forecasting:a hybrid approach to address the influence of passenger flow fluctuations

Train timetables and operations are defined by the train running time in sections,dwell time at stations,and headways between trains.Accurate estimation of these factors is essential to decision-making for train delay reduction,train dispatching,and station capacity estimation.In the present study,we aim to propose a train dwell time model based on an averaging mechanism and dynamic updating to address the challenges in the train dwell time prediction problem(e.g.,dynamics over time,heavy-tailed distribution of data,and spatiotemporal relationships of factors)for real-time train dispatching.The averaging mechanism in the present study is based on multiple state-of-the-art base predictors,enabling the proposed model to integrate the advantages of the base predictors in addressing the challenges in terms of data attributes and data distributions.Then,considering the influence of passenger flow on train dwell time,we use a dynamic updating method based on exponential smoothing to improve the performance of the proposed method by considering the real-time passenger amount fluctuations(e.g.,passenger soars in peak hours or passenger plunges during regular periods).We conduct experiments with the train operation data and passenger flow data from the Chinese high-speed railway line.The results show that due to the advantages over the base predictors,the averaging mechanism can more accurately predict the dwell time at stations than its counterparts for different prediction horizons regarding predictive errors and variances.Further,the experimental results show that dynamic smoothing can significantly improve the accuracy of the proposed model during passenger amount changes,i.e.,15.4%and 15.5%corresponding to the mean absolute error and root mean square error,respectively.Based on the proposed predictor,a feature importance analysis shows that the planned dwell time and arrival delay are the two most important factors to dwell time.However,planned time has positive influences,whereas arrival delay has negative influences.

变负载机械手轨迹跟踪控制器设计

本文针对具有变负载的不确定刚性机械手系统,提出了一种依赖平均驻留时间的神经网络自适应切换控制策略.本控制方案将夹持不同负载的刚性机械手系统视为切换系统,即根据负载的不同将整个系统分为若干子系统,并基于平均驻留时间原则对每个子系统分别设计控制器.在各子系统中,分别采用径向基函数(RBF)神经网络逼近系统结构参数,以避免控制器对系统精确模型的依赖.同时,基于神经网络设计鲁棒补偿项,以抑制集总扰动对系统的影响.然后,利用多Lyapunov函数方法证明了轨迹跟踪误差的一致最终有界性.最后,通过仿真验证,所提出的控制方案不仅可实现变负载机械手期望轨迹的高精度跟踪,而且可有效削弱输入力矩的抖振.

含执行器故障的切换非线性系统的事件触发自适应模糊容错控制

本文研究在平均驻留时间约束下,一类含有执行器故障的切换非线性系统输出反馈自适应模糊事件触发容错控制问题.首先,建立了一个模态依赖的状态观测器估计不可测量状态.利用模糊逻辑系统来逼近未知项.其次,构建自适应模糊容错事件触发控制方案能够节省网络资源和数据传输.然后,通过构造多Lyapunov函数和平均驻留时间法,证明闭环系统所有状态半全局一致最终有界的同时排除了Zeno现象.最后,通过数值仿真验证该方法的有效性.

Robust exponential stability of uncertain discretetime impulsive switching systems with state delay

A new class of hybrid impulsive and switching models are introduced and their robust exponential stability and control synthesis are addressed. The proposed switched system is composed of stable subsystems and unstable subsystems, which not only involves state delay and norm-bounded time-varying parameter uncertainties, but also contains the impulsive switching effects between the subsystems. Based on the extension of the system dimension and the concept of average dwell time, a kind of practically useful switching rule is presented which guarantees the desired robust exponential stability. A switched state feedback controller is also given.

Stability of Switched Positive Descriptor Systems with Average Dwell Time Switching

In this paper, the problems of stability for a class of switched positive descriptor systems(SPDSs)with average dwell time(ADT) switching are investigated. First, based on the equivalent switched system and the properties of the projector matrix, sufficient stabilities are given for the underlying systems in both continuoustime and discrete-time contexts. Then, a sufficient stability condition for the SPDS with both stable and unstable subsystems is obtained. The stability results for the SPDSs are represented in terms of a set of linear programmings(LPs) by the multiple linear co-positive Lyapunov function(MLCLF) approach. Finally, three numerical examples are given to illustrate the effectiveness of the obtained theoretical results.

Stabilization of switched linear systems under asynchronous switching subject to admissible edge-dependent average dwell time

The problem of stabilizing switched linear systems under asynchronous switching is addressed.The admissible edge-dependent average dwell time method is applied to design a switching signal that comprises slow admissible edge-dependent average dwell time and fast admissible edge-dependent average dwell time.Under this switching signal,the restriction that the maximum delay of asynchronous switching is known in advance is removed.The constructed Lyapunov function is associated with both the system mode and controller mode.The stabilization criteria and the corresponding algorithm are presented to obtain the controller gains and to design the switching signal.Finally,two examples are given to demonstrate the effectiveness of the proposed results.

Robust Exponential Stability of Discrete Time Perturbed Impulsive Switched Systems

The robust exponential stability of a class of discrete time impulsive switched systems with structure perturbations is studied. Based on the average dwell time concept and by dividing the total activation time into the time with stable subsystems and the time with unstable subsystems, it is shown that if the average dwell time and the activation time ratio are properly large, the given switched system is robustly exponentially stable with a desired stability degree. Compared with the traditional Lyapunov methods, our layout is more clear and easy to carry out. Simulation results validate the correctness and effectiveness of the proposed algorithm.

H_-/H_∞ fault detection filter design for interval time-varying delays switched systems

The problem of the robust fault detection filter design for time-varying delays switched systems is considered in the framework of mixed H-/H∞. Firstly, the weighted H∞ performance index is utilized as the robustness performance, and the H- index is used as the sensitivity performance for obtaining the robust fault detection filter. Then a novel multiple Lyapunov-Krasovskii function is proposed for deriving sufficient existence conditions of the robust fault detection filter based on the average dwell time technique. By introducing slack matrix variable, the coupling between the Lyapunov matrix and system matrix is removed, and the conservatism of results is reduced. Based on the robust fault detection filter, residual is generated and evaluated for detecting faults. In addition, the results of this paper are dependent on time delays,and represented in the form of linear matrix inequalities. Finally,the simulation example verifies the effectiveness of the proposed method.

Pose Synchronization of Multiple Rigid Bodies Under Average Dwell Time Condition

这份报纸在交换在哪儿的拓扑学下面考虑一组动人的僵硬身体的姿势同步问题每拓扑学的居住时间可以没有非零更低的界限。作者介绍一个平均居住时间条件描绘图在被连接的时间间隔的长度。由设计尖速度和线性速度的分布式的控制法律，有交换拓扑学的多重僵硬身体的靠近环的动力学能被变换成一个混合动态系统。作者采用 Lyapunov 稳定性定理，并且证明姿势同步能在平均居住时间条件下面被到达。而且，作者在一个类似的平均居住时间条件下面调查领导人追随者模型的姿势同步问题。模拟例子被给说明结果。

Robust H_∞ static output feedback control of discrete-time switched polytopic linear systems with average dwell-time

This paper investigates the problem of robust exponential H∞ static output feedback controller design for a class of discrete-time switched linear systems with polytopic-type time-varying parametric uncertainties. The objective is to design a switched static output feedback controller guaranteeing the exponential stability of the resulting closed-loop system with a minimized exponential H∞ performance under average dwell-time switching scheme. Based on a parameter-dependent discontinuous switched Lyapunov function combined with Finsler＇s lemma and Dualization lemma, some novel conditions for exponential H∞ performance analysis are first proposed and in turn the static output feedback controller designs are developed. It is shown that the controller gains can be obtained by solving a set of linear matrix inequalities （LMIs）, which are numerically efficient with commercially available software. Finally, a simulation example is provided to illustrate the effectiveness of the proposed approaches.

Event-Triggered Finite-Time <i>H</i>_∞Control for Switched Stochastic Systems

This paper investigates the problem of event-triggered finite-time H∞ control for a class of switched stochastic systems. The main objective of this study is to design an event-triggered state feedback H∞ controller such that the resulting closed-loop system is finite-time bounded and satisfies a prescribed H∞ level in some given finite-time interval. Based on stochastic differential equations theory and average dwell time approach, sufficient conditions are derived to ensure the finite-time stochastic stability with the prescribed H∞ performance for the relevant closed-loop system by employing the linear matrix inequality technique. Finally, the desired state feedback H∞ controller gain matrices can be expressed in an explicit form.

Caputo分数阶切换线性系统的指数稳定性

众所周知,与整数阶切换系统不同, Caputo分数阶切换系统的积分下界不能随子系统的切换而被更新,意味着在下界非一致的任意区间内不能直接取分数阶导数的分数阶积分.对此,本文给出了一个不等式(文中引理6)克服这一问题,并用1个数值例子进行了验证.通过这一不等式,然后分别利用多Lyapunov函数方法和模型依赖平均驻留时间(MDADT)方法,给出了Caputo分数阶切换线性系统指数稳定的条件,并利用2个数值例子进行验证.

具有时变时滞的离散时间切换奇异正系统的l_(1)滤波

该文主要研究了一类具有时变时滞的离散时间切换奇异系统在正性约束下的l_(1)滤波器的设计问题.通过构造合适的共正Lyapunov函数并且利用平均驻留时间的方法,以线性规划的形式给出使得相应的滤波误差系统是正的、正则的、因果的、指数稳定的充分条件.另外,外部扰动输入对系统性能的影响也被加以分析和讨论,并在稳定性的基础上进一步给出滤波误差系统具有给定l_(1)增益性能的充分条件和相应滤波器的设计方法.最后,通过数值算例来验证所给方法的有效性和可行性.

具有随机网络攻击的切换信息物理系统的事件触发控制

本文研究了随机网络攻击下切换信息物理系统的事件触发控制问题.将信息物理系统描述为一种切换线性系统形式.引入事件触发机制来节省系统资源和减轻网络负载,当误差超过给定阈值时传感器中的采样数据才通过通信网络传输到控制器中.考虑在传感器与控制器的通信网络中受到两种不同特征的随机网络攻击.在网络攻击和所设计的事件触发控制器下,建立了切换随机信息物理系统模型.利用模态依赖平均驻留时间方法构建了相应的切换信号.在设计的事件触发控制器和模态依赖平均驻留时间切换信号下实现了系统的均方指数稳定性,并给出了控制器增益.最后,通过实例验证了所得理论结果的有效性.

一类切换随机系统的事件触发控制

研究了切换随机系统的事件触发控制问题,为避免Zeno行为和减少不必要的通信传输,提出一种基于采样数据的事件触发控制方案。首先,假设控制器可以获取系统状态和开关信号的同步采样信息。利用合并切换信号技术,将闭环系统建模为具有状态误差和增广切换信号的切换随机系统。然后,通过多重李雅普诺夫函数方法和范数放缩,获得了充分的均方指数稳定性条件。同时,给出了切换随机系统的稳定控制器设计方法。最后,通过数值仿真验证了方法的有效性。

Robust fault detection for delta operator switched fuzzy systems with bilateral packet losses

Considering packet losses, time-varying delay, and parameter uncertainty in the switched fuzzy system, this paper designs a robust fault detection filter at any switching rate and analyzes the H∞ performance of the system. Firstly, the Takagi-Sugeno(T-S) fuzzy model is used to establish a global fuzzy model for the uncertain nonlinear time-delay switched system,and the packet loss process is modeled as a mathematical model satisfying Bernoulli distribution. Secondly, through the average dwell time method and multiple Lyapunov functions, the exponentially stable condition of the nonlinear network switched system is given. Finally, specific parameters of the robust fault detection filter can be obtained by solving linear matrix inequalities(LMIs). The effectiveness of the method is verified by simulation results.

隐蔽攻击下线性离散切换系统的区间观测器设计

为解决网络控制系统中状态安全估计问题,研究了线性离散切换系统在隐蔽攻击下区间观测器的设计问题。首先依据隐蔽攻击的条件,得到攻击信号的边界估计。其次针对切换系统构造出能分别估计状态上界和下界的区间观测器。将系统受到的有界干扰与攻击向量视为增广状态变量,构造出增广系统。在满足平均驻留时间条件约束下,采用Lyapunov函数方法,设计出系统切换律,使得切换系统全局指数稳定并满足鲁棒加权H∞性能指标。然后求解线性矩阵不等式,得到切换系统区间观测器参数及增益矩阵,从而有效地获得系统状态边界估计。最后给出的仿真结果表明该区间观测器设计的有效性。

异步切换下δ算子切换系统的可靠保成本控制

该文研究异步切换下δ算子切换系统的可靠保成本控制问题.首先基于模态依赖平均驻留时间法和多凸Lyapunov函数法,对δ算子切换系统的全局一致指数稳定性进行分析并给出满足保成本控制性能的异步状态反馈控制器存在的充分条件.其次设计了异步状态反馈保成本控制器.最后以数值算例的方式说明了方法的有效性.

线性离散切换系统的区间观测器设计

为解决线性切换系统状态区间估计问题,基于原坐标系下设计了一种能给出系统上下边界估计值的区间观测器.首先针对切换系统构造出能分别估计状态上界和下界的观测器,其次将系统受到的有界干扰与测量噪声向量视为增广状态变量,构造出增广系统.在该增广系统的基础上引入更多的参数设计自由度,减少区间观测器的设计约束与保守性,使得估计误差对扰动具有良好的鲁棒性.在满足平均驻留时间约束的切换信号下,使用多Lyapunov函数方法,使得切换系统全局指数稳定并满足加权H_(∞)性能指标.然后求解线性矩阵不等式,得到切换系统区间观测器参数及增益矩阵,从而有效地获得系统精确的状态边界估计.最后给出的数值仿真算例证实了该区间观测器方法的有效性.