Steady-State Wide-Range Air-Fuel Ratio Control

An experimental system for closed-loop control of air-fuel ratio in a fuel-injected engine using a universal exhaust gas oxygen (UEGO) sensor is described. A model incorporating feed forward and feedback control is characterized for steady- state and feed-forward errors, and response to slowly varying engine load disturbances. The system is implemented on a port fuel injected 4.6L V8 engine with commercially available components, including a universal microcomputer based engine controller and a UEGO sensor and signal conditioning package. The performance of the experimental system is compared with the simulation results and practical limitations of the modeled control system.