The development of control system for an automobile is often the most critical phase along the road to launching a new vehicle. Over the years there has been a significant advancement in the technology for faster and smarter design of ECUs (Engine control Unit). Model based engine control system design is a stage-by-stage structured process for design and optimization of control functions for various automotive control applications
This paper discusses various examples of engine and controller models and there software-in-loop simulation results for application like air-fuel ratio control, idle speed control and knock control. The objective here is to develop a Model Based Control (MBC) for a Port Fuel Injection (PFI) engine. The engine and controller model has been developed using Matlab and Simulink 7.0.
Mean Value Engine Model (MVEM) for air-fuel ratio control and idle speed control, and cyclic engine model for knock control are discussed. A PID controller model using Lambda sensor feedback for air-fuel ratio control, and Idle speed controller model using controlled ignition timing, controlled air flow with a bypass valve and their combination is evaluated. Knock model also discussed by using in-cylinder pressure data.
The Air Fuel Ratio (AFR) and idle speed controller models were simulated in- loop against the mean values engine model. The PID controller parameters were tuned at various points on engine mapping for target overshoot and settling time and a look-up table for these parameters was fed into the controller. The knock controller model was simulated in loop with the cycle engine model. The open loop response of the controller is presented in this paper.
