| With the incessant improvement of people's living standards,the increasing amount of diesel vehicles has caused a sharp increase in environmental pollution and energy consumption.Otherwise,due to diesel engine national sixth emission regulations,power,economy and other requirements,automotive diesel engines will face severe chalenges.Forcing people to continuously study diesel engine control technology and emission control technology,so that diesel engines will develop rapidly toward low emissions and high thermal efficiency.And these important technologies need to rely on the ECU to achieve its specific functions.The underlying driver software is one of the important foundations for the ECU to achieve its functions.Therefore,it is very significant to research develop the underlying driver software that meets the national six emission standards.Taking D30 TCI high-pressure common rail diesel engine as the control object,researched the control technology route of light-duty and heavy-duty diesel engine that met the requirements of the national six emission regulations.According to this control technology route,the demand analysis of the ECU underlying driver software and MCU was carried out and selected Multi-core microcontroller TC275 of Infineon was the main control chip of ECU.Rationally alocated TC275 on-chip resources and designed the ECU overall scheme by means of sub-modules.Based on the overall ECU solution,researched several key driving software algorithms for the underlying software of ECU of high pressure common rail diesel engine that met the requirements of the national six emission regulations:1 ? The phase tracking recognition algorithm,filtering,frequency multiplication and fault handling mechanism of crankshaft and camshaft.2 ? Control method and fault diagnosis mechanism of fuel injection solenoid valve.3 ? The flexible control algorithm of fuel metering unit.4 ? The control strategy and flexible control algorithm of VNT actuator and EGR valve.5?The effect of DOC coupled DPF on the conversion efficiency of CO,HC and PM,as well as the different working conditions and temperature on conversion efficiency,SCR's NOx emission control system for heavy-duty diesel engines and the effect of different temperatures on NOx conversion efficiency,the principle of LNT technology and the influence of exhaust temperature on NOx adsorption efficiency.The detailed scheme design of ECU underlying driver software was completed,including crankshaft camshaft signal processing and fault handling scheme,the underlying driver software solution for joint cylinder of crankshaft camshaft,the underlying driver software solution for single crankshaft cylinder,the underlying driver software solution for single camshaft cylinder,the underlying driver software solution for fuel injection solenoid valve,the underlying drive software solution for fuel metering unit,the underlying drive software solution for VNT actuator,the underlying drive software solution for EGR valve,the underlying drive software solution for urea nozzle,the acquisition scheme of diesel engine temperature sensor,pressure sensor,position sensor,flow sensor,NOx concentration sensor Actuator drive current for VADC.Solved the problem that the diesel engine could go home when a single position sensor failed.Reduced power consumption and complexity of software design for the fuel injection system.Improved the reliability of the fuel injection underlying drive software.Improved the precision injection control of urea solution.Reduced NH3 leakage.The diesel engine could quickly establish stable and reliable rail pressure and provided different boost pressure and EGR rate under various operating conditions of starting,idle speed,low speed,medium and high speed,low load and high load.Integrated the underlying driver software of each module and verified by Hardware-in-the-loop experiment and bench tests.1 ?The designed under-cylinder driving software could accurately and quickly determine the TDC of each cylinder at different speeds,and accurately calculated the injection timing of each cylinder based on the angle and time-based injection duration of each cylinder.The accuracy was 0.01 °CA.2 ?The injector valve drive current quickly reached about 18 A at 84?s,and it was quickly turned off within 50?s,so the high-speed on-off response was alright.Moreover,the driving current fluctuation range was ±5%.The driving current waveform was stable,which had high reliability and anti-interference ability.3 ? The underlying driving software of the fuel metering unit could flexibly adjust the frequency and duty cycle of the fuel metering unit control signal,thereby controlled the opening of the fuel metering unit to achieve the rail pressure demand of the diesel engine under different working conditions.4?VNT actuator and EGR valve underlying drive software ccould flexibly change the duty cycle of each control signal and the direction of DC motor rotation,thus changed the VNT nozzle ring flow area and EGR valve opening to achieve boost pressure and EGR rate demand under different diesel engine conditions.5 ?The urea nozzle drive current was controlled by current feedback,so that the drive current fluctuation range was ±9.7%.6?A number of diesel engine ignition experiments were carried out and all were able to start stably. |
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