Stuck-at fault

About: Stuck-at fault is a research topic. Over the lifetime, 9707 publications have been published within this topic receiving 160254 citations.

A gate-level simulation environment for alpha-particle-induced transient faults

Abstract: Mixed analog and digital mode simulators have been available for accurate /spl alpha/-particle-induced transient fault simulation. However, they are not fast enough to simulate a large number of transient faults on a relatively large circuit in a reasonable amount of time. In this paper, we describe a gate-level transient fault simulation environment which has been developed based on realistic fault models. Although the environment was developed for /spl alpha/-particle-induced transient faults, the methodology can be used for any transient fault which can be modeled as a transient pulse of some width. The simulation environment uses a gate level timing fault simulator as well as a zero-delay parallel fault simulator. The timing fault simulator uses logic level models of the actual transient fault phenomenon and latch operation to accurately propagate the fault effects to the latch outputs, after which point the zero-delay parallel fault simulator is used to speed up the simulation without any loss in accuracy. The environment is demonstrated on a set of ISCAS-89 sequential benchmark circuits.

Observer-Based Adaptive Fault-Tolerant Tracking Control of Nonlinear Nonstrict-Feedback Systems

Abstract: This paper studies an output-based adaptive fault-tolerant control problem for nonlinear systems with nonstrict-feedback form. Neural networks are utilized to identify the unknown nonlinear characteristics in the system. An observer and a general fault model are constructed to estimate the unavailable states and describe the fault, respectively. Adaptive parameters are constructed to overcome the difficulties in the design process for nonstrict-feedback systems. Meanwhile, dynamic surface control technique is introduced to avoid the problem of “explosion of complexity”. Furthermore, based on adaptive backstepping control method, an output-based adaptive neural tracking control strategy is developed for the considered system against actuator fault, which can ensure that all the signals in the resulting closed-loop system are bounded, and the system output signal can be regulated to follow the response of the given reference signal with a small error. Finally, the simulation results are provided to validate the effectiveness of the control strategy proposed in this paper.

Fault Estimation and Fault-Tolerant Control for Discrete-Time Dynamic Systems

Abstract: In this paper, a novel discrete-time estimator is proposed, which is employed for simultaneous estimation of system states, and actuator/sensor faults in a discrete-time dynamic system. The existence of the discrete-time simultaneous estimator is proven mathematically. The systematic design procedure for the derivative and proportional observer gains is addressed, enabling the estimation error dynamics to be internally proper and stable, and robust against the effects from the process disturbances, measurement noise, and faults. Based on the estimated fault signals and system states, a discrete-time fault-tolerant design approach is addressed, by which the system may recover the system performance when actuator/sensor faults occur. Finally, the proposed integrated discrete-time fault estimation and fault-tolerant control technique is applied to the vehicle lateral dynamics, which demonstrates the effectiveness of the developed techniques.

A detailed model of induction machines with saturation extendable for fault analysis

Abstract: A review of the literature suggests that modeling of induction machines with saturation has received considerable attention Most of these models are very application specific None of them, however, seems to be completely adequate for the purpose of fault diagnosis This is because for a noninvasive detection technique such as Motor Current Signature Analysis (MCSA), one has to detect different frequency components in the line current of the machine Incorporation of saturation in the induction machine model will help in identifying and analyzing harmonics in the line current spectra that may arise due to the interaction of saturation with a specific fault The present paper attempts to create such a model The model uses modulation of air-gap permeance in order to emulate saturation Modified winding function approach (MWFA) has been used to model the induction machine with saturation To demonstrate the effectiveness of the model, certain high-frequency harmonics that can be predicted theoretically are shown to be present in the line current of the simulated machine Experimental results also confirm the presence of these harmonics The author plans to extend this model in the future for fault analysis

A Decision Tree-Based Method for Fault Classification in Double-Circuit Transmission Lines

Abstract: In this paper, a novel method for fault classification of double-circuit transmission lines is presented. The proposed method needs voltages and currents of only one side of the protected line. After detecting the exact time of fault inception and calculating the odd harmonics of the measured signals, up to the nineteenth, a decision tree algorithm has been employed for recognition of the intercircuit fault type. Also, the proposed method is extended for classification of crossover faults in these transmission lines. Simulation results have shown that the proposed method can classify the faults in less than a quarter of a cycle with the highest possible accuracy.