جستجوی مقالات مرتبط با کلیدواژه « sensor fault » در نشریات گروه « فنی و مهندسی »

In this paper, fault-tolerant controller design problem for Lipschitz nonlinear fractional-order systems in presence of sensor fault is considered. By using the descriptor system theory, a correct estimation of the state vector is achieved and then by using it, a stabilizing state feedback controller is designed. By employing some appropriate techniques, parameters design of the observer and controller are stated in terms of linear matrix inequalities, which there exist powerful toolbox for solving them. The proposed observer can estimate the correct value of the sensor fault vector, thus, it can be utilized for the fault detection, isolation, and identification unit.  Besides, the structure of the proposed method is such that the observer and controller design can be performed independently, which facilitate the design process. The effectiveness of the proposed method is shown with numerical simulation results.

This paper deals with the design of an unknown input observer (UIO) with the assumption that the well-known observer matching condition is not satisfied. The proposed method can be used for fault detection problems with the use of residual vector. The basis of method is to compensate the unmatched uncertainties with the use of a set of auxiliary outputs. The introduced auxiliary outputs are obtained from successive integration of the system measurements and known inputs. Then, an unknown input observer is proposed which estimates exponentially the outputs. Therefore, the residual vector, generated from the estimated outputs and the actual outputs, will be obtained which insensitive to the unmatched disturbances. At the same time, the sensitivity of the proposed residual vector to the fault in sensors is investigated. The generated residual vector will be more robust against the presence of noise in the measurements. It is shown through numerical simulations that the proposed residual vector is sensitive to the presence of fault in sensors while it is insensitive to the presence of the unknown input. In addition, a comparison with a derivative based method is presented.