A proposed method to controller parameter soft tuning as accommodation FTC after unknown input observer FDI

• Main Authors: Hashemi S.M., Abyari M., Barati S., Tahmasebi S., Talati S.
• Other Authors: 57192714769
• Format: Article
• Published: Asian Research Publishing Network 2023
• Institution: Universiti Tenaga Nasional

The problem of Fault Tolerant Control (FTC) by the use of methods of fault accommodation and reconfiguration is one of the most updated and versatile problems of modern science in control systems engineering. Occurrence of a fault in every components of a system (actuators, sensors, and internal structure) can remove the control loop from the desired state or even destabilize it. The purpose of the fault tolerant control by the accommodation method is to present operational solutions, by the use of which the control loop stability can be maintained and an acceptable performance is obtained (probably weaker than the no-fault condition) in fault occurrence conditions without the need to shut down the system. In this paper, the fault detection and isolation (FDI) issue has been investigated including the fault of system actuators. Design of a fault detection system for a multi-input multi-output (MIMO) system has been done by the method of Unknown Input Observer (UIO). In this method, the system is divided into several sub-systems in a way that the effects of other inputs are entered into states equations as a disturbance. The design method of the observer is such that the disturbance effect is attenuated and only the fault related to a particular input is detected. Having detected and isolated a fault, controlling coefficients are iteratively updated and modified using an auto-tuning method and the closed loop system stability is ensured in the presence of the method. In addition, in order to reduce the oscillation resulting from exerting momentary changes in controlling coefficient, a modification method known as the Sigma modification has been used. Next, the method is implemented on the favorite model of three tanks and the results confirm capability of the designed fault detection system and quality of auto-tuning of the controller. � 2006-2016 Asian Research Publishing Network (ARPN).