Design of Active Fault-Tolerant Control System for Air-Fuel Ratio control of Internal Combustion engine using...

Area of Science:

• Engineering
• Control Systems
• Automotive Engineering

Background:

• Internal Combustion (IC) engines are vital in the process sector, requiring precise Air-Fuel Ratio (AFR) control for optimal performance, fuel efficiency, and emissions.
• Sensor faults in AFR systems can lead to critical engine shutdowns, necessitating robust fault-tolerant strategies.

Purpose of the Study:

• To propose a novel Active Fault-Tolerant Control System (AFTCS) for AFR regulation in IC engines to prevent engine shutdown due to sensor failures.
• To enhance the fault tolerance and reliability of AFR control systems in process plant applications.

Main Methods:

• Development of an AFTCS utilizing a nonlinear regression-based observer model for analytical redundancy within the Fault Detection and Isolation (FDI) unit.
• Simulation of the proposed system in MATLAB/Simulink and testing at engine speeds of 300 r/min and 600 r/min.

Main Results:

• The AFTCS demonstrated acceptable system response and stability at tested speeds.
• The system exhibited superior fault tolerance for sensor defects, particularly the MAP sensor, showing reduced oscillations compared to existing methods.
• The nonlinear regression model provided more accurate sensor fault estimation than linear regression or Genetic Algorithm (GA) models.

Conclusions:

• The proposed AFTCS effectively enhances fault tolerance in IC engine AFR control systems.
• The nonlinear regression approach offers improved accuracy, efficiency, and response time for fault detection and isolation, crucial for preventing engine shutdowns.