A passive fault-tolerant control strategy for a non-linear system: An application to the two tank conical non-interacting level control system

Abstract

In practical engineering systems, unknown actuator, sensor or system component faults frequently occur, which results from component and interconnection failures, degrade control performance, system stability, and profitability, and even arise hazardous situation. To avoid abnormal activity like faults and maintain system control performance subject to faults occurring into the system, the Fault-tolerant Control (FTC) is a realistic approach to address the unwanted situation. The two-tank conical system is widely used in chemical and food process industries because of its greater advantages. The non-interacting configuration of the two-tank conical system is highly nonlinear due to its shape and varying area of the tank thought the height of the tank, as a consequence level control of this system is extremely difficult. The paper attributes to design a Passive Fault-tolerant Control Strategy (PFTCS) for a Two-tank conical Non Interacting Level Control System (TTCNILCS) subject to the major system (leak), sensor, and actuator faults with external process disturbances. PFTC will increase system control performance and system stability acceptable level in the presence of sensor, system, and actuator faults. The simulation results demonstrate the proposed PFTC strategy has definite fault tolerant ability against the system and actuator faults also it has good disturbance rejection capability. To verify the efficacy of the proposed PFTC strategy Mean Square Error (MSE) and Root Mean Square Error (RMSE) Integral Absolute Error (IAE) indices are used.

Keywords

• actuator fault
• process disturbance
• non-interacting system
• nonlinear
• neural network
• passive fault-tolerant control
• system fault.