Katherin Indriawati

Reconfigurable Controller Based on Fuzzy Descriptor Observer for Nonlinear Systems with Sensor Faults

In this paper, the FTC system for multiple operating condition nonlinear systems subjected to sensor faults is developed by applying reconfigurable control scheme. The scheme generates any modified control signal using appropriate additive reference signal to the nominal control system. The proposed observer is developed based on descriptor approach in the fuzzy Takagi-Sugeno model configuration in order to accommodate some operating conditions of a nonlinear system. The simulation result shows that the proposed method has capability to compensate more than one sensor fault occurred in a three-tank benchmark system even there is a change in condition operation as well as in reference signal.

Fault tolerant control system design for vacuum effect evaporator plant with sensor and actuator fault

As the final part of the Multi-Effect Evaporator (MEE) unit, Vacuum Effect Evaporator (VEE) will determine the product quality and efficiency of the petrochemical plant. Control systems that work on VEE must have high performance and reliability. This paper proposes a fault tolerant control system (FTCS) scheme for VEE to accommodate sensor fault and actuator fault that can occur simultaneously. This scheme consists of two things, namely: detection and error diagnosis by using an observer and control signal reconfiguration mechanism with compensation technique. As a real case study, simulated VEE is based on a petrochemical plant in West Java province. Simulation results show that the proposed FTCS is able to compensate for both in the sensor and actuator faults simultaneously, so that the stability and overall system performance remains optimal.

Reconfigurable fault-tolerant control of linear system with actuator and sensor faults

This paper presents an active fault-tolerant control for linear system in case of actuator and sensor faults where these minor faults lead to degraded performance of the system. Three steps are proposed to achieve fault tolerant control based on simplified analytical redundancy. Firstly, a bank of linear observer is proposed to estimate the actuator and sensor faults by modeling a descriptor LTI system using the SVD technique. Secondly, the estimated faults are used to design a fault decision scheme to detect the faults correctly. Thirdly, a reconfigurable fault-tolerant control scheme is designed by using the estimated faults to compensate the fault effects on controller performance. Simulation on the three tank system is given to illustrate the performance of the proposed method.