Research And Development Of Hardware Control System For Natural Gas/diesel Dual Fuel Engines

Beijing,hebei and other places of continuous haze weather has a huge impact on people's physical and mental health,thus solving the problem of air pollution has become urgent.The development of diesel/CNG dual fuel automobile provides a feasible solution for air pollution.Dual fuel automobile compared to the traditional diesel engine has a great advantage on emissions,economy and noise control.By analyzing the electronic control unit(ECU)control demand for CNG/diesel dual fuel engine,dual fuel engine needs through 20 channel sensors to capture real-time condition information and 18 actuator control the engine running.Due to the complicate control mechanism and the large MAP storage space of dual fuel engine,so you need to select a high-performance single chip microcomputer as main control chip of dual fuel engine.TC 1782 as infineon main single chip microcomputer of automobile power system,it use tricore architecture,the highest frequency of up to 180 MHZ,internal integration 2.5 M PFlash,has 32 channels A/D captue channel,86 digital I/O channels,and integrated with GPTA module is used for processing fast PWM signal.Therefore,TC1782 can meet the needs of the dual fuel engine control.According to the requirements of the dual fuel engine sensors,actuators,MCU and other functional requirements,design the corresponding sensor signal processing circuit,actuator drive circuit,single chip microcomputer minimum system circuit and other circuit.According to different types of sensor signals,respectively,designed the ? type analog signal processing circuit,switch signal isolation circuit and pulse signal hysteresis comparison circuit.According to different types of actuators,respectively,designed solenoid valve drive circuit,brushless dc motor drive circuit and the relay drive circuit.Because of the injector of high pressure common rail fuel injection system have high injection pressure,high control precision,fast response speed,need to adopt double voltage driving circuit design.The advantage is can not only meet the requirements of fuel injector rapid response,but also obtain the ideal waveform Peak-Hold,and prevent damage of injector solenoid coil overheating.After the completion of the circuit principle diagram,layout PCB.Because of the dual fuel ECU circuit board include switching power supply module,large current driver module and analog signal module,so it is importantof circuit board components layout and line.Are previous quality problem of PCB,the land of the division,sensitive module isolation protection and heat dissipation of high power devices is fuly considered in the process of PCB layout.Dual fuel ECU functional debugging rely on the hardware in the loop system which development of the laboratory.Adding a set of gas injection devices on the basis of the YN38CRD2 for bench experiments,conducted the pure diesel and natural gas/diesel dual fuel experiments,the experimental results show that the development of the dual fuel engine ECU hardware circuit meet the design requirements.