This paper presents an engine management system to control a 4-stroke two-cylinder motorcycle engine. At the heart of the system is a microcontroller based reference design engine control unit. This works together with a crank wheel sensor, throttle position sensor, oxygen sensor, manifold pressure sensor, injectors, ignition coils and fuel pump.
This system has the capability to detect engine position, sense throttle position, calculate mass airflow from air temperature, control fuel injection timing and amount, control spark timing and dwell. It has idle control with stepper motor and closed-loop feedback of oxygen levels in the exhaust. To achieve fast closed-loop control, the controller turns on an oxygen heater. Serial communication via KWP2000 is used for reprogramming of the controller and reading diagnostic codes.
The main goal of this system is to meet emission requirements and provide OBD capability. Some results on an actual motorcycle will be presented. This paper will also present the system's diagnostic capabilities using smart drivers in the controller and the embedded software. In addition to the system, a proper PC based monitor & calibration tool with graphic user interface for development work will be introduced.