Research And Development Of ECU For Natural Gas / Diesel Dual Fuel Electronic Control Engine

The dual fuel engine (Natural Gas/Diesel) can effectively reduce emissions and realize the diversification of energy utilization. Thesis topics taken from related corpus of Yunnan province science and technology plan projects, in view of the dual fuel engine ECU hardware development were studied.This dual fuel engine was refitted by the Yunnei Power YN38CRD2 common rail diesel engine. According to the requirements of dual fuel engine control system, the control systems of gas-jet was designed, including jet solenoid valve driver, current sensing and valve driver circuit and so on; electronic control system of common rail diesel engine was designed based on Infineon TC1782 microcontroller, including the MCU minimum system, power modules, fuel injection control circuit, VNT and EGR driver, glow plugs and rail pressure control module; the sensor signal conditioning circuit was designed, including crankshaft camshaft, water temperature, rail pressure, the accelerator pedal, intake air flow rate and temperature and so on.According to the requirements of ECU driver circuit’s interference and crosstalk, the PCB’s key parts were designed as the following:(1) For PCB layout, the digital GND, analog GND and power GND were sub-regional and don’t overlap inter-layer, connected the lowest potential point together, which greatly reduces the interference between the GNDs. (2) Taking fully account of PCB cooling and the electromagnetic radiation of high current drive circuit, the driver circuit and sensor signal conditioning circuit layout sub-regional and following 3W alignment rules, reducing PCB internal interference. (3) According to the minimum loop of law parallel layout actuator drive circuit on the same floor, reducing drive crosstalk between the actuators.The results of hardware in loop test (HIL) and bench test for the electronic control system hardware shown that:1) HIL test platform was established, which including 4-way driver solenoid valve injector and 4-way driver of jet valve solenoid based on the TC1782, the injector driver current Peak-Hold test results shown that:Injection Solenoid in 100μs reach 18A, turn-off time 20μs, meet the injector’s on and off rapid requirements, current stability is better. Jet solenoid valve Peak current up to 8A of 1.2ms rapidly reduced to Hold current of 6A within 300μs, fully meet the requirements of natural gas injection.2) Tested for fuel metering unit, signal conditioning circuit and other functional modules, the results shown that all can meet the relevant requirements.3) For bench testing, obtain the crankshaft and camshaft signal by Laboratory developed LabECU could realize synchronization sequence with the ECU supply gas, real-time and control accuracy requirements were meet.4) The testing from steady start to idle for Common Rail engine driver board shown that the engine can start quickly completed within 1.5 s, the engine idling condition operate smoothly and without knocking, black smoke and so on.