International Journal of applied mathematics and computer science

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Paper details

Number 1 - March 2020
Volume 30 - 2020

Fault tolerant multicontrollers for nonlinear systems: A real validation on a chemical process

Sondess Mejdi, Anis Messaoud, Ridha Ben Abdennour

An active sensor fault tolerant controller for nonlinear systems represented by a decoupled multimodel is proposed. Active fault tolerant control requires accurate fault estimation. Thus, to estimate both state variables and sensor faults, a discrete unknown input multiobserver, based on an augmented state multimodel, is designed. The multiobserver gains are computed by solving linear matrix inequalities with equality constraints. A multicontrol strategy is proposed for the compensation of the sensor fault and recovering the desired performances. This strategy integrates a bank of controllers, corresponding to a set of partial models, to generate a set of control laws compensating the fault effect. Then, a switching strategy between the generated local control laws is established in order to apply the most suitable control law that tolerates the fault and maintains good closed loop performances. The effectiveness of the proposed strategy is proven through a numerical example and also through a real time application on a chemical reactor. The obtained results confirm satisfactory closed loop performance in terms of trajectory tracking and fault tolerance.

multicontroller, experimental validation, transesterification reactor, discrete unknown input multiobserver, fault tolerant control, sensor fault estimation