Research Of Universal ECU Used In Electrical Controlled Diesel Engine Based On Simulation

With the shortage of energy supply and strict requirements to environ-ment, modern diesel engine needs to become more economical and lower emission. Electrical controll is the only way to fulfill these strict require-ments. Among the different type of electrically controlled diesel engine, Electrically Unit Pump (EUP) fuel injection system and high pressure common rail (CR) fuel injection system is the most common solution. Ac-cording to the requirements of diesel engine market, a universal Electronic Control Unit(ECU) for electrically controlled diesel engine is designed in this thesis. By little adjustments of hardware and software, this ECU can be used to control both fuel systerm. This ECU is powerful, reliable and suita-ble for mass production.The major work of this thesis is the hardware research, design and tests of universal ECU by the way of simulation. The main research in this thesis is listed as follows:1. The required modules of universal ECU used by electrically con-trolled diesel engine are designed based by reading many literatures. The universal ECU, which uses advanced 32-bit microcontroller,is not only powerful, but also reliable and universal. By little adjustments of hardware and software parameters, universal ECU can be used in different cylinder diameter, different cylinder numbers of both EUP and high pressure com-mon rail diesel engine. The universal ECU can also receive different sensor signals and switch signals and drive different type of relays, lamps and sig-nals. The ECU also has powerfully vehicle control functions, which can meet the most requirements of diesel engine market.2. Accoding to the chanllenge of small package, low costs and high re-liability, a develop method based on simulation is put forward and success- fully implemented in the design of universal ECU, which greatly reduce the research time and research costs of universal ECU. The function of each circuit module is designed by simulation. The various factors which affects the electrical responsivity of solenoid driving module is analysed based on the simulation of solenoid driving module. The close responsivity of sole-noid is shortened from 230μs to 35μs by optimization.3. According to status of small package, high ambient working temper-ature and great peak power dissipation and difficult heat transfer path of universal ECU, the power dissipation is also analysed by simulation in this thesis. The maxium power dissipation of ECU is reduced from 96W to 38.2W by optimization. At the same time, the efficiency of high voltage power supply module upgrade from 72.3% to 87.6% by simulation. The power dissipation of each power component at different engine speed and engine load is carefully simulated and analyzed. The maximal power dissi-pation of each device at all possible engine running status is carried out in this thesis. According to these simulations and analysis, the thermal design of universal ECU is put forward in this thesis. The tests show that the ther-mal design fully meets the harsh running temperature of ECU.4. The reliability design and tests of universal ECU is carried out in this paper. The self-protection function of solenoid driver module can protect the module at the failure of actor or software. It also provides sigal for hardware and software diagnose. The tests show that the peak driving current at the short status of solenoid is 24A while the current is 50A by software diagnose. The equivalent EMI (Electro Magnetic Interference) of solenoid drive mod-ule is also created. By application of simulation and optimization, the vol-tage oscillation and current oscillation is successfully emitted, which greatly reduced EMI of ECU.5.Many engine bench tests and road tests have been applied with this univsal ECU. The tests of vehicle mounted with universal ECU in ultra high termperautre enverioment, ultra low temperature environment and ultra high altitude environment have been applied in this paper. These tests show that the universal ECU is powerfull and reliable.