Robust Passive Fault Tolerant Control for Air Fuel Ratio Control of Internal Combustion Gasoline Engine for Sensor and Actuator Faults

This paper presents a novel Passive Fault Tolerant Control System (PFTCS) for Air Fuel Ratio (AFR) control system of the Internal Combustion (IC) gasoline engine to prevent its shutdown. A Proportional plus Integral (PI) controller with high feedback gain is implemented to control AFR by introducing a fuel throttle valve in the fuel line of the engine. The salient feature of the proposed controller is its less complex structure due to the absence of Analytical Redundancy (AR). Dual redundancy in the hardware is suggested for the sensors to prevent tripping in case of coincident faults in multiple sensors and for the actuator assembly to confiscate a single point of failure. The robustness of the proposed PFTCS is tested by introducing noise in the sensor measurements. MATLAB / Simulink environment simulation results demonstrate that the proposed PFTCS is robust to faults in normal as well as noisy conditions of the sensors without any degradation of AFR. The stability analysis of the proposed controller is performed by determining the poles of the closed-loop system. The reliability analysis of the proposed controller has been performed by calculating the probabilistic reliability function of the model. The comparison of the proposed model with the existing models has also been carried out to elaborate its effectiveness.