A computer-based simulation and test system for the calibration of EFI engine

When the EFI system is used in a specific engine, lots of experiments are needed to optimize the control data (MAP). This work is time and financial consuming. This paper aims to develop a computer-based simulation and test system, which can produce the initial control MAP with good accuracy, and calibrate the ECU on-line. So the experiments are reduced and calibration is accelerated. In order to improve the accuracy of the initial control data, the mathematical models are built not only based on theoretical equations, but also on the control data of typical operation points, which is obtained by the on- line calibration of specific engines. This system can also perform some special calibrations, like "constant pulse width" and "square wave modulation." "Constant pulse width" calibration is used to continuously vary the A/F ratio by changing intake airflow, and the "square wave modulation" is used to identify the engine dynamic transfer function for A/F control, idle speed control and ignition timing control. The application of this system on a mini- car shows that the simulated control MAP has good accuracy, and the interface of the system is friendly. The combination of simulation and test makes the system very powerful for EFI engine calibration, in the same time the development speed is accelerated.