Wyniki wyszukiwania - BazTech

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ARMAX-based identification and diagnosis of vibration behavior of gas turbine bearings

Mahroug Youcef, Khaldi Belgacem Said, Guemana Mouloud, Hafaifa Ahmed, Iratni Abdelhamid, Colak Ilhami

Diagnostyka

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2023

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Vol. 24, No. 3

art. no. 2023310

EN

Parametric identification approaches play a crucial role in the control and monitoring of industrial systems. They facilitate the identification of system variables and enable the prediction of their evolution based on the input-output relationship. In this study, we employ the ARMAX approach to accurately predict the dynamic vibratory behavior of MS5002B gas turbine bearings. By utilizing real input-output data obtained from their operation, this approach effectively captures the vibration characteristics of the bearings. Additionally, the ARMAX technique serves as a valuable diagnostic tool for the bearings, enhancing the quality of identification of turbine variables. This enables continuous monitoring of the bearings and real-time prediction of their behavior. Furthermore, the ARMAX approach facilitates the detection of all potential vibration patterns that may occur in the bearings, with monitoring thresholds established by the methodology. Consequently, this enhances the availability of the bearings and reduces turbine downtime. The efficacy of the proposed ARMAX approach is demonstrated through comprehensive results obtained in this study. Robustness tests are conducted, comparing the real behavior observed through various probes with the reference model, thereby validating the approach.

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Different Approaches to Model Relationship Between EMG Signals and Force Moments in Human Skeletal Muscle. Analysis for Diagnosis of Neuronmuscular Disorders

Brzostowski K., Świątek J.

Fundamenta Informaticae

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2009

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Vol. 96, nr 4

465-475

EN

In the paper five different models have been examined in order to test their ability to describe relationship between EMG and force moment generated by moving upper or lower limb. In system analysis point of view it can be utilised for diagnostic purpose i.e. conversing subjective methods using by physician to new one based on objective measured data.

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A hybrid algorithm for the PEM estimation of ARMAX structures

Koulocheris D., Dertimanis V.

Foundations of Computing and Decision Sciences

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2005

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Vol. 30, No. 4

309-320

EN

This paper proposes a new methodology for the estimation of ARMAX models, based on the implementation of a hybrid optimisation algorithm and a corresponding estimation procedure. The specific algorithm attempts to interconnect the diverse characteristics of two entirely different optimisation techniques, deterministic and stochastic, combining high convergence rate with increased reliability in the search for global optimum, and it consists of a super-positioned stochastic global search, followed by an independent deterministic procedure, in which the analytical gradients of the ARMAX model are used. The corresponding estimation procedure is split into two parts, due to the mixed linear-nonlinear relationship between the prediction errors and the parameter vector, and assures the stability and invertibility of the resulted models. The parametric identification test case, which is considered in this study, refers to the estimation of an ARMAX model for the description of a half-car passive suspension system of a road vehicle.