Hardware And Software Development Of Electronic Control System For Gas Fuelled Internal Combustion Engine

In recent years, expanding car ownership in China indicates a rapid growing fuelconsumption. Gas alternative fuel such as CNG, LPG, COG, Hydrogen is more andmore widely applied to the internal combustion engine. The main purpose of designelectronic control system for gas engine is to make full use of the gas alternative fueland develop a gas engine with good power, low fuel consumption and low emission.The developing process of electrical control system based on EQD210N-20CNG engine includes hardware updating, control strategy optimization and systemcalibration.Hardware updating consists of main chip circuit designing, input signalprocessing circuit designing, driver circuit designing, communication circuitdesigning, power module designing and connector designing. The key task isas follows: design new injector driver module with good stability and less heatrelease; design UEGO control module to suit the AF closed loop controlsystem for lean-burn engine； design CAN communication circuit as thehardware interface for monitoring system and calibration system; re-match thepower module to make a stable and reliable5V supply.Control strategies mainly include the input signal measurement, runningcondition judgment, running parameter calculation and calculation result implement.Control strategies are very different under various working conditions. Therefore,they are also divided into start mode, idle mode, open throttle mode and transientmode. And in open throttle mode, AF feedforward control algorithm and AF feedbackcontrol algorithm can both be used.System calibration is carried out according to different engine operatingconditions. Key control parameters are determined after lots of experiments in startmode, idle mode and open throttle mode.Finally the electronic control system for gas engine is tested on the test bench,the results shows the system is stable and reliable with good power output.