Fault detection of networked dynamical systems (NDSs) has attracted ever-increasing attention since it can maintain high-quality products as well as operational safety. Considering the utilisation ...

https://www.tandfonline.com/doi/pdf/10.1080/00207721.2021.1998722

Fault detection of networked dynamical systems: a survey of trends and techniques

In this paper, the reliable control problem of nonlinear singularly perturbed systems subject to random actuator faults is studied. A Takagi-Sugeno fuzzy model is utilized to describe the nonlinear plant, and a Markov chain with partly unknown transition probabilities is adopted to characterize the random behaviors of the actuator faults, in contrast with the existing fault modes in which all the transition probabilities are required to be known. Combining the utilization of a novel fuzzy singular-perturbation-parameter-dependent Markovian Lyapunov function with the introduction of the slack matrix variable, sufficient conditions on the existence of the reliable fuzzy controller are presented, which are dependent on the upper bounds on the time derivatives of membership functions. A search algorithm is provided to obtain the maximum stabilization bound. Moreover, conditions based on single Lyapunov function are also established. The effectiveness and the applicability of the proposed new design technique are verified by an example of an electronic circuit system.

Reliable Control of Fuzzy Singularly Perturbed Systems and Its Application to Electronic Circuits

This paper concerns the stabilization problem of stochastic uncertain complex-valued delayed networks (SUCVDNs) via aperiodically intermittent nonlinear control. It is worth noting that the intermittent control is aperiodic and nonlinear. As a special case, when each control width tends to zero, intermittent control becomes impulsive control. Hence, the stabilization problem of SUCVDNs via impulsive control is also studied. The main method is the combination of the Lyapunov method and Kirchhoff’s matrix tree theorem in graph theory, which does not require us to solve any linear matrix inequalities. Different from previous results on complex-valued system, we consider the complex-valued system on complex space directly by using complex version Ito’s formula and (conjugate) ${\mathbb {R}}$ derivative. Then we give some sufficient criteria, which have a close relationship with the control interval and the topological structure of the considered network. The main results are applied to a class of stochastic complex-valued coupled oscillators, and numerical examples are also presented to show the effectiveness of the control strategies.

Stabilization of Stochastic Uncertain Complex-Valued Delayed Networks via Aperiodically Intermittent Nonlinear Control

This article proposes a fault-tolerant compensation control approach against nonlinearity, simultaneous additive, and multiplicative actuator faults in Markov jump systems. In this article, we first exploit the fuzzy logic system (FLS) to approximate the nonlinear functions, which have no available knowledge. Then, by utilizing the adaptive backstepping technique, a FLS-based adaptive fault-tolerant compensation controller is proposed, which can completely compensate for the adverse effects, arising from the additive actuator faults, the multiplicative actuator faults, and the mismatched nonlinearity simultaneously. The stability of the closed-loop system can be guaranteed by the proposed FLS-based adaptive controller with the adaptation laws. The novelty of this article lies in the fact that the additive and multiplicative actuator faults, and mismatched nonlinearity are considered simultaneously. Besides, the renown sliding mode control approach has limitations to deal with the FTC problem considered in this article because the considered nonlinearity is a mismatched one. The proposed control approach can cope with the challenging case. Finally, a practical wheeled mobile manipulator system is used to demonstrate the effectiveness and validity of the proposed approach.

Adaptive Fuzzy Fault-Tolerant Control for Markov Jump Systems With Additive and Multiplicative Actuator Faults

This paper investigates the problem of event-based security control for state-dependent uncertain systems under hybrid-attacks. An event-triggered scheme is adopted to mitigate the communication burden, where the sampled data are delivered only when the predefined triggering condition is violated. Meanwhile, a new hybrid-attacks model, which contains denial-of-service attacks and replay attacks, is established to describe the randomly occurring cyber-attacks. By taking hybrid-attacks into account, a novel mathematical model for state-dependent uncertain systems with event-triggered scheme is established. Then, through employing Lyapunov–Krasocskii stability theory and linear matrix inequality techniques, sufficient conditions ensuring the state-dependent uncertain systems being exponentially mean-square stable are deduced. Based on the derived sufficient conditions, the desired output feedback controller gain is obtained. Finally, the feasibility of the proposed method is demonstrated by a numerical example, and the applicability of the developed theoretical results is also illustrated by the controller design for electronic circuits.

Event-Based Security Control for State-Dependent Uncertain Systems Under Hybrid-Attacks and Its Application to Electronic Circuits

This paper mainly studies the fault detection (FD) problem for linear discrete time-varying systems subject to random sensor delay. By assuming that the measurement channel is with Transmission Control Protocol (TCP), an observer-based FD filter (FDF) is provided as a residual generator via embedding the packet indicator into the filter. To construct this FDF, its design issue is formulated into two sub-problems. One is to maximize the $\mathcal {H}_{-}/\mathcal {H}_{\infty }$ or $\mathcal {H}_{\infty }/\mathcal {H}_{\infty }$ FD performance index, which aims to enhance the ratio of fault sensitivity/disturbance attenuation. The other one is to find the filter parameter matrices such that the error between the residual and the fault is minimized in the $\mathcal {H}_{\infty }$ sense. By employing stochastic analysis and introducing some adjoint operator based optimization approaches, analytical solutions to the aforementioned FDF design problem are derived via solving recursive Riccati equations. An illustrative example is given to show the effectiveness of the proposed methodologies.

Fault Detection for Linear Discrete Time-Varying Systems Subject to Random Sensor Delay: A Riccati Equation Approach

The molecular compressibility, which is a macroscopic quantity to reveal the microcompressibility by additivity of molecular constitutions, is considered as a fixed value for specific organic liquids. In this study, we introduced two calculated expressions of molecular adiabatic compressibility to demonstrate its pressure and temperature dependency. The first one was developed from Wada&#x2019;s constant expression based on experimental data of density and sound velocity. Secondly, by introducing the 2D fitting expressions and their partial derivative of pressure and temperature, molecular compressibility dependency was analyzed further, and a 3D fitting expression was obtained from the calculated data of the first one. The third was derived with introducing the pressure and temperature correction factors based on analogy to Lennard-Jones potential function and energy equipartition theorem. In wide range of temperatures and pressures , which represent the typical values used in dynamic injection process for diesel engines, the calculated results consistency of three formulas demonstrated their effectiveness with the maximum 0.5384&#x25; OARD; meanwhile, the dependency on pressure and temperature of molecular compressibility was certified.

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Macroscopic Expressions of Molecular Adiabatic Compressibility of Methyl and Ethyl Caprate under High Pressure and High Temperature

An adult gait extraction and anomaly analysis method based on Kinect mainly comprises the following steps of: (1) collecting adult traveling videos, and solving and obtaining adult traveling gait space-time parameters based on foot end track analysis and lower limb inverse kinematics; (2) performing deduction based on the lower limb inverse kinematics to calculate Z-Y-X Euler angles and step lengths of hip joints, knee joints and ankle joints of an adult; (3) calculating the maximum value, the minimum value, the mean value and the variance of each joint angle in each set of data to obtain datacomprising the joint angles, the step lengths and the gait time parameters; and (4) employing a K-S single simple to inspect and obtain distribution conditions of the parameters, and combining the Pauta criterion to obtain the normal ranges of the parameters. On the basis of collection of adult gait parameters, small samples are analyzed based on the related knowledge of the probability and mathematical statistics to obtain the normal ranges of the parameters and provide reference for doctors' clinical analysis.

Adult gait extraction and anomaly analysis method based on Kinect

The invention discloses a biped robot kinematic analysis method based on toddler gait extraction. The method comprises the following steps: (1) walking videos of a toddler in different months are acquired, and corresponding supporting phases, oscillating phases, uniped or biped supporting phases, a gait cycle and a step frequency are extracted; (2) based on a D-H pose conversion method, a human lower limb coordinate system is built, skeletons of thighs, lower legs and soles are regarded as connecting rods, parts driving the skeletons to move are regarded as joints connecting the connecting rods, and a corresponding D-H parameter table is solved; (3) a forward kinematic model and an inverse kinematic model of the lower limb are solved; and (4) change values of joint angles are subjected tocurve fitting to analyze the spatial characteristics of a toddler walking gait. On the basis of acquiring the toddler walking data and extracting the gait time parameters, the forward kinematic modeland the inverse kinematic model of the lower limb are deduced based on the D-H pose conversion method, a toddler gait development space parameter change law is thus acquired, and a theoretical supportcan be provided for gait planning for the biped robot.

Biped robot kinematic analysis method based on toddler gait extraction

This paper presents a leader-following framework by stereo-vision, which allows quadruped robots to adapt to challenging outdoor environments. Our framework relies on the deeply supervised object detector (DSOD) detection framework and the kernelized correlation filter (KCF) tracker. The algorithm can enhance the cognitive ability of robots and lay a foundation for the autonomy of robots in outdoor environments. Without the use of pre-trained models, DSOD is a framework for training object detectors from scratch, with greater accuracy than state-of-the-art detectors. We propose an improved tracker based on traditional KCF with multi-feature fusion and multi-scale estimation. Pedestrian re-identification and relocation are introduced to mitigate effects of strong vibration, scale variation, occlusion, and illumination variation. To compensate for the possible transient balance loss caused by short tracking drift, the heading angle of the robot is smoothed and filtered. Outdoor experiments with the quadruped robot show the effectiveness and robustness of this framework.

Qin Zhang

Papers

Fault Detection for Linear Discrete Time-Varying Systems Subject to Random Sensor Delay: A Riccati Equation Approach

Macroscopic Expressions of Molecular Adiabatic Compressibility of Methyl and Ethyl Caprate under High Pressure and High Temperature

Adult gait extraction and anomaly analysis method based on Kinect

Biped robot kinematic analysis method based on toddler gait extraction

ALeader-following Method Based on Binocular Stereo Vision For Quadruped Robots