Parameter estimation of uncertain nonlinear MIMO three tank systems using higher order sliding modes

Bhatti

2009 IEEE 13th International Multitopic Conference

et al. 2009

Self Cite

A synthesis of parameter estimation based fault diagnosis scheme for uncertain nonlinear systems using higher order sliding modes is presented. The uncertain parameters of nonlinear system are estimated using an uncertainty estimator or observer. The estimated parameters carry information about system and actuator faults. A fault signal representing the dynamics of the fault is reconstructed using the estimated parameters and comparing it with the nominal (fault free) values of the corresponding parameters. For the fault free case, the magnitude of the fault reconstructed signal 'residual' remains close to zero and a fault declared when the magnitude of the reconstructed fault signal becomes non-zero and crosses some predefined threshold. To validate the technique, simulations have been carried out for an uncertain nonlinear MIMO Three Tank System. Proposed fault diagnosis technique requires no prior information about the uncertain/unknown system parameters and statistical knowledge of process.Index Terms-Fault detection and isolation, parameter estimation, uncertain nonlinear systems, differentiator observer, higher order sliding modes, three tank system. I.

Section: A Estimation Of the Parametersmentioning

confidence: 99%

Section: A Estimation Of the Parametersmentioning

confidence: 99%

See 1 more Smart Citation

Parameter estimation based fault diagnosis of uncertain nonlinear three tank system using HOSM differentiator observer

Bhatti

2009 IEEE 13th International Multitopic Conference

et al. 2009

Self Cite

2010 11th International Workshop on Variable Structure Systems (VSS)

“…In this work the proportionality parameter has been estimated via an observer, a dynamical system using input-output measurements. Model-based observers are being used at large scale for estimation of model parameters [4][5][6][7][8][9][10][11][12][13][14][15]. The employed techniques include.…”

Section: Introductionmentioning

confidence: 99%

“…This is the reason that the research community is more attracted to the technique. The technique applied in a variety of industrial applications in recent years [7][8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Parameter estimation of PEMFC system with unknown input

Kazmi

Bhatti

Iqbal³

2010

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This paper presents the synthesis of a model-based robust observer with an unknown input that observes a state (manifold pressure) of Fuel Cell System (FCS) in the presence of uncertainties. Using this observer the proportionality constant of the inlet manifold orifice is estimated. Then this estimated parameter is used to calculate the time varying air mass flow. As the mass flow rates of reactant gases play a pivotal role in the reliable and efficient operation of FCS. Their precise and exact value is necessary and important for the control and diagnostics of FCS. In the particular sense of inlet manifold of fuel cell system, appropriate air mass flow is very critical for the proper maintenance of chemical reactions taking place in the cathode and anode chambers. The sliding mode observer (SMO) with super twisting algorithm is utilized for the estimation of the mass flow rate of air despite the unknown input (load current). The estimates come out to be quite close to the nominal values. The simulation results show robustness to the uncertainties and fast convergence of estimates to nominal values of the parameter. The chattering phenomenon is attenuated significantly by employing higher order sliding mode. The standard SMO results are also presented for the sake of comparison. The proposed strategy is useful for sensor reduction, fault diagnostics and control.

Optim Control Appl Methods

Discrete‐time systems sliding mode switching hyperplane design: A survey

Luis-Delgado

Al‐Hadithi

Jiménez

2019

Summary As regards to variable structure control with sliding mode (VSC‐SM), it is known that designing sliding surface is a critical task because sliding surfaces must guarantee that the steady state of the controlled system achieves some desired performance including global (or global asymptotic) stability. This problem has been extensively analyzed for a wide class of systems: scalar, multivariable, linear, nonlinear, time‐variant, discrete‐time system, etc. The main purpose of this paper is to present a thorough survey about the main approaches related to the design of discrete‐time switching surfaces applied to VSC‐SM. Research works covering the design of sliding surfaces for the aforementioned systems are considered and some illustrative examples are also included to explain some of the design methodologies.