共轨喷油器在车喷油量控制自学习方法

为了精确控制喷油器老化后的在车喷油量,分析了共轨喷油器老化试验前后的小油量喷射特性,提出了小油量自学习修正的方法。当发动机处于倒拖工况时,在不同的轨压下,通过主动小脉宽喷射测得特定缸角加速度与其他几缸角加速度平均值的比值,研究得到发动机小油量燃烧后角加速度变化规律,并据此设计喷油量控制自学习算法。实车试验与台架试验表明,在无需增加额外传感器的情况下,小油量自学习修正算法能精确控制老化喷油器的小油量,明显改善老化喷油器小油量喷射的一致性和稳定性,满足发动机在全寿命期间的性能要求。

Self-learning Method of On-board Injection Control for Common Rail Injector

In order to control the on-board injection quantity of aging injector precisely,the small injection quantity characteristics of common rail injector before and after the aging test were analyzed and the self-learning method of correcting the small injection quantity was proposed.When the engine was dragging,the ratio of specific cylinder angular acceleration and other cylinder average angular acceleration could be measured by the active small pulse injection under different rail pressures.The change of angular acceleration after small injected fuel combustion was researched and the self-learning algorithm of fuel injection was designed.The vehicle and bench tests show that the self-learning correction method of small injection quantity can control the small injection quantity of aging injector accurately,which improves the consistency and stability of small injection quantity for aging injectors and meets the engine performance requirement in the whole life.