Sliding-mode observers for systems with unknown inputs and measurement disturbances

The method to design sliding-mode observers for systems with unknown inputs and measurement disturbances is presented in the paper. An augmented system is constructed by viewing the measurement disturbances as unknow inputs. For such an augmented system, the so-called observer matching condition is not satisfied. Based on the construction of auxiliary outputs, the observer matching condition may be satisfied. High-order sliding-mode differentiators are developed to obtain the estimates of those unmeasurable variables contained in the auxiliary output vector. Employing the estimate of auxiliary output vector, a sliding-mode observer is designed. The simulation results to a real model show that the proposed method is effective.

Measurement-induced disturbance and nonequilibrium thermal entanglement in a qutrit qubit mixed spin XXZ model

We investigate the dynamics of nonequilibrium thermal quantum correlation of a qutrit-qubit mixed spin system coupled to two bosonic reservoirs at different temperatures using measurement-induced disturbance. The effects of initial states of the spins and temperatures of the reservoirs on measurement-induced disturbance and entanglement are discussed. The results demonstrate that measurement-induced disturbance is more robust than entanglement against the influence of both these factors and there is no sudden death phenomenon for measurement-induced disturbance. The dependences of steady-state measurement-induced disturbance and entanglement on coupling constant and anisotropy parameter are also studied. Steady-state entanglement vanishes for a ferromagnetic qutrit-qubit model, while steady- state measurement-induced disturbance exists for both the antiferromagnetic and ferromagnetic cases. Appropriately modulating the coupling constant and anisotropy parameter can strengthen quantum correlation.

Fault reconstruction observer design for continuous-time systems with measurement disturbances via descriptor system approach

This paper addresses a problem of observer-based sensor fault reconstruction for continuous-time systems subject to sensor faults and measurement disturbances via a descriptor system approach. An augmented descriptor plant is first formulated,by assembling measurement disturbances and sensor faults into an auxiliary state vector. Then a novel descriptor state observer for the augmented plant is constructed such that simultaneous reconstruction of original system states, sensor faults and measurement disturbances are obtained readily. Sufficient conditions for the existence of the proposed observer are explicitly provided, and the application scope of the observer is further discussed. In addition,an extension of the proposed linear approach to a class of nonlinear systems with Lipschitz constraints is investigated. Finally, two numerical examples are simulated to illustrate the effectiveness of the proposed fault-reconstructing approaches.

Indoor measurement method of smoke screen disturbance efficiency based on Gaussian diffusion model

Because of ground clutter wave interf e rence,it is difficult to measure smoke screen disturbance in the field.In this pape r,a kind of indoor measurement method of smoke screen disturbance efficiency ba sed on Gaussian diffusion model is put forward.As a characteristic,the measur ement result of smoke screen area density proves that the indoor measurement met hod of smoke screen disturbance efficiency based on Gaussian diffusion model is fea sible.

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

This paper deals with the problem of active disturbance rejection control(ADRC)design for a class of uncertain nonlinear systems with sporadic measurements.A novel extended state observer(ESO)is designed in a cascade form consisting of a continuous time estimator,a continuous observation error predictor,and a reset compensator.The proposed ESO estimates not only the system state but also the total uncertainty,which may include the effects of the external perturbation,the parametric uncertainty,and the unknown nonlinear dynamics.Such a reset compensator,whose state is reset to zero whenever a new measurement arrives,is used to calibrate the predictor.Due to the cascade structure,the resulting error dynamics system is presented in a non-hybrid form,and accordingly,analyzed in a general sampled-data system framework.Based on the output of the ESO,a continuous ADRC law is then developed.The convergence of the resulting closed-loop system is proved under given conditions.Two numerical simulations demonstrate the effectiveness of the proposed control method.

Research on the anti-disturbance issues of the breakout prediction system in continuous casting

This paper introduces the function,structure and alarm principles of the breakout prediction system installed for continuous casting in Baosteel's No.2 Steelmaking Plant.It elaborates on four parameters in the alarm logic,including the temperature changing rate,temperature difference,temperature fluctuation and temperature match of thermocouples.This paper also explains the causes of different disturbances within the breakout prediction system,and the methods used to prevent and eliminate disturbances from radiation,earth,crosstalk,temperature drift and time drift.Finally,the paper summarizes some potential applications of the above technology.

Measurement-induced disturbance in Heisenberg XY spin model with Dzialoshinskii-Moriya interaction under intrinsic decoherence

Quantum correlations measured by measurement-induced disturbance(MID) in a two-qubit Heisenberg XY spin model with Dzialoshinskii–Moriya(DM) interaction under intrinsic decoherence are investigated. MID is studied under various circumstances and the influences of the external dependencies on the final quantum state which has stable MID are discussed. Two kinds of initial quantum states are considered as well as different conclusions. MID appears to decay periodically during the processing of intrinsic decoherence; both DM interaction and intrinsic decoherence have a negative impact on the correlations. The MID of the stable state depends on several factors, except the parameter of the intrinsic decoherence. Moreover, we find a special initial state that is able to maintain the maximum quantum correlations during the processing of intrinsic decoherence.

Measurement-induced disturbance between two atoms in Tavis-Cummings model with dipole dipole interaction

Quantum correlation, measured by measurement-induced disturbance(MID), between two two-level atoms is investigated in detail in Tavis–Cummings model with dipole–dipole interaction(DDI). We find that MID can be determined only by the dipole–dipole interaction between the two atoms when the cavity and atoms are at resonance. Moreover, DDI will have different effects on MID for two different kinds of initial states.

Output Feedback Regulation for 1-D Anti-Stable Wave Equation with External System Disturbance

This paper has studied the output feedback regulation problem for 1-D anti-stable wave equation with distributed disturbance and a given reference signal generated by a finite-dimensional exosystem. We first design an observer for both exosystem and auxiliary PDE system to recover the state. Then we show the well-posedness of the regulator equations and propose an observer-based feedback control law to regulate the tracking error to zero exponentially and keep all the states bounded.

Boundary Exponential Stabilization of a One-Dimensional Anti-Stable Wave Equation with Control Matched Disturbance

In this paper, we are concerned with output feedback stabilization for a one-dimensional anti-stable wave equation with disturbance. First, we design a disturbance estimator for the original system. Then, we propose an output feedback controller for the original system. By calculation, the closed-loop of original system is proved to be exponentially stable and well-posed. Finally, this paper is summarized.

Study on Anti-Disturbance and High-Resolution Shallow Seismic Exploration of Active Faults in Urban Regions

The significance of detection of urban active faults and the general situation concerning detection of urban active faults in the world are briefly introduced. In a brief description of the basic principles of anti-disturbance and high-resolution shallow seismic exploration, the stress is put on the excitation of seismic sources, the performance of digital seismographs, receiving mode and conditions, geometry as well as data acquisition, processing and interpretation in the anti-disturbance and high-resolution shallow seismic exploration of urban active faults. The study indicates that a controlled seismic source with a linear or nonlinear frequency-conversion scanning function and the relevant seismographs must be used in data acquisition, as well as working methods for small group interval, small offset, multi-channel receiving, short-array and high-frequency detectors for receiving are used. Attention should be paid to the application of techniques for static correction of refraction, noise suppressing, high-precision analysis of velocity, wavelet compressing, zero-phasing of wavelet and pre-stacking migration to data processing and interpretation. Finally, some cases of anti-disturbance and high-resolution shallow seismic exploration of urban active faults are present in the paper.

Robust fault diagnosis with disturbance rejection and attenuation for systems with multiple disturbances

The fault diagnosis problem is investigated for a class of nonlinear neutral systems with multiple disturbances.Time-varying faults are considered and multiple disturbances are supposed to include the unknown disturbance modeled by an exo-system and norm bounded uncertain disturbance.A nonlinear disturbance observer is designed to estimate the modeled disturbance.Then,the fault diagnosis observer is constructed by integrating disturbance observer with disturbance attenuation and rejection performances.The augmented Lyapunov functional approach,which involves the tuning parameter and slack variable,is applied to make the solution of inequality more flexible.Finally,applications for a two-link robotic manipulator system are given to show the efficiency of the proposed approach.

Simultaneous measurements of global vibrational spectra and dephasing times of molecular vibrational modes by broadband time-resolved coherent anti-Stokes Raman scattering spectrography

In broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy with supercontinuum (SC),the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth.By numerical simulations,the optimal experimental conditions for improving the SC are obtained.The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised.The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement.At the same time,the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals.It will be more helpful to provide a complete picture of molecular vibrations,and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions,but also the mechanisms of chemical reactions in the fields of biology,chemistry and material science.

MEASUREMENT AND COMPUTATION OF THE PSEUDO-RESONANCE AND ANTI-RESONANCE

This paper presents a phenomenon of“Pseudo-resonance”of beams androds discovered from experiments and computations,and gives the definition of“Pseudo-resonance”.The relationship of distribution between the frequency of pseu-do-resonance and that of anti-resonance is found,and an analytic solution for thetransfer function between any two points on a beam or rod is established.The law ofdistribution of the anti-resonant frequencies,as well as the relation between the fre-quency distribution and the nodes of vibration is also proposed.

带宽化调节下的抗扰PID退饱和控制方法

比例–积分–微分(PID)控制的抗饱和设计是一类经典非线性控制问题,理论研究丰富,但工程中广泛使用的仍是积分退饱和这类简易策略.究其原因,现有理论方法过于依赖系统模型和状态空间理论,稳定性条件与调参机制之间关系复杂.本文基于经典退饱和控制结构,首次阐述了“退饱和带宽”概念及退饱和参数调节机理,在此基础上讨论了两类低阶退饱和补偿器的带宽化设计方法.在抗扰PID反馈控制下,结合小增益定理得到退饱和控制的稳定性条件,给出控制参数与退饱和带宽之间的调节关系,实现退饱和控制的带宽化整定.最后,通过数值仿真验证了所提方法的有效性.

新时代中国民众反腐败效能感:本土概念与量表构建

意愿等心理机制是决定民众积极有序参与反腐败活动的重要因素,反腐败效能感概念的提出与测量正是对于这一问题的学理性探讨。反腐败效能感涵盖民众基于自我能力认知的内部效能感和基于对反腐败政策发生效用的外部效能感,其中对于具体反腐败政策的评价、对于不同层级的官员廉洁形象的评价以及对于反腐败参与意愿的倾向性态度等是中国本土的独有特征。基于民众反腐败效能感的微观测量为构建反腐倡廉宏观方略的长效动力机制提供了科学依据,对于提升国家治理能力现代化、实现从严治党背景下反腐倡廉工作的深入进行具有重要的知识积累和政策咨询意义。

基于广域测量的汽轮发电机励磁反步控制方法

由于汽轮发电机励磁反步控制过程中没有实时获取发电机的运行数据,致使电机励磁反步控制效果较差,为此提出基于广域测量的汽轮发电机励磁反步控制方法。通过广域测量系统的同步相量测量单元,实时采集汽轮发电机功角与电流等运行数据,将采集的运行数据变更成标幺值形式,根据该形式建立汽轮发电机励磁控制的数学模型,获取励磁反步控制变量,并结合反步法,设计汽轮发电机励磁反步控制器,通过径向基函数神经网络估计控制器内的扰动,完成控制器扰动补偿。实验结果表明:该方法可精准采集汽轮发电机运行参数,有效反步控制汽轮发电机励磁,令汽轮发电机功角与转子角速度等迅速恢复至稳定状态,具备较优的反步控制效果;应用该方法后,可确保电网运行稳定性,降低故障后电网切机量。

基于运行扰动数据分析的低压台区拓扑辨识方法研究

传统的低压台区拓扑识别方法具有精确度低、抗干扰能力差、效率低等一系列问题。针对上述问题,提出一种基于电流运行扰动数据的台区拓扑辨识方法。利用改进的灰色关联分析法对测量终端采集的低压出线柜、分支箱、光力柜、表箱的电流扰动数据进行分析,计算低压台区不同部分数据的相关性,实现台区供电隶属关系识别。通过电流确定台区中各部分的进出线连接关系,实现对台区拓扑的识别。算例结果表明,利用电流扰动数据进行台区拓扑辨识具有准确度高、效率高的特点,因此在实际应用中更具价值与潜力。

一些常见分布族的反集中函数

假定{X_(α)}为一族服从某类分布的随机变量,具有有限期望E[X_(α)]和有限方差Var(X_(α)),其中α为一参数.受Hollom和Portier的论文(arXiv:2306.07811v1)的启发,在本文中我们考虑反集中函数(0,∞)∋y→inf_(α)P(|X_(α)-E[X_(α)]|≥y√Var(X_(α))),并给出其清晰表示.我们将证明,对于某些常见分布族,包括均匀分布、指数分布、非退化高斯分布和学生t分布,反集中函数不恒为零,这表明相应随机变量族具有某种反集中性质;然而对另外一些常见分布族,包括二项分布、泊松分布、负二项分布、超几何分布、伽马分布、帕雷托分布、威布尔分布、对数正态分布和贝塔分布,反集中函数恒为零.

我国《反外国制裁法》追偿诉讼条款的适用研究

追偿诉讼是一国阻断法的私人实施路径,其主要功能在于阻却外国法律及相关判决的域外适用,从我国《反外国制裁法》第十二条的性质、目的和功能上判断,该条规定属于阻断性质的追偿诉讼条款。在借鉴域外阻断立法追偿诉讼条款适用经验的基础上,我国应在谦抑性原则的理念下对《反外国制裁法》第十二条规定的“我国公民、组织”“任何组织和个人”“歧视性限制措施”等用语进行谨慎的界定,同时应积极制定后续实施细则,完善相关法律法规的配套保障条款,以明确第十二条追偿诉讼条款的请求权基础、管辖权依据、判决的执行途径等适用过程中的具体问题,从而保障《反外国制裁法》追偿诉讼条款的真正实施。