高压共轨柴油机喷油控制策略研究

通过对高压共轨柴油机喷油控制的需求分析,发现在转速突变时进气系统具有明显的迟滞性,这种迟滞性表现为进气增量跟不上喷油增量,所设计的转速变化主喷油量修正算法能够重新修正原喷油量,以获得合理的空燃比,改善燃烧过程。多次喷射会造成轨压波动,经过多次喷射轨压波动油量修正算法对喷油量脉宽进行预修正,可以提高喷油执行精度。利用ETAS公司的ASCET建模软件工具和自主开发的ECU电路板,在YN33CR型高压共轨柴油机上进行了台架试验。试验结果表明:该喷油控制策略符合预期效果,能够有效改善喷油控制。

Injection Control Strategy of High Pressure Common Rail Diesel Engine

Through analyzing requirements of injection control of high pressure common rail diesel engine, the air intake system had obvious hysteresis in the changing speed. And this kind of hysteretic performance was represented that the increment of the intake-air could not obviously keep pace with the increment of the injection. Thus, the designed correction algorithm of main injection quantity for changing speed could newly modify the original main injection fuel quantity, and obtain the reasonable air-fuel ratio and optimize the combustion process. For the fluctuation of common rail pressure was caused by the multiple injection, the fuel correction algorithm of multiple injection for common rail pressure fluctuation could pre-rectify the fuel injection pulse width and improve the injection accuracy, which were realized by using the ASCET modeling software tools of ETAS company and the independently developed ECU circuit board. After calibration experiment of the engine on YN33CR high pressure common rail diesel engine, such as starting and idling condition test, main injection quantity correction test of changing speed, fuel correction test of multiple injection for rail pressure fluctuation, constant torque and increasing speed mode test, constant speed and increasing torque mode test, the results showed that the fuel injection control strategies achieved the expected results and it can effectively improve the injection control.