喷油自学习策略在发动机怠速控制中的应用

Application of auto-learning strategy of fuel injection in engine idle speed control

为降低车辆冷起动暖机阶段怠速波动,设计基于转速波动的喷油自学习控制策略,在传统比例积分微分(proportional integral differential,PID)控制中增加基于转速波动的喷油调节环节,监测转速波动形态,对喷油脉宽进行修正。进行实车试验,研究相同环境边界的怠速稳定一致性,并对比分析执行喷油自学习策略前、后的转速波动及转速波动概率分布。结果表明:执行喷油自学习策略前,怠速转速一致性较差,怠速控制无法收敛,转速波动大于±50 r/min;执行喷油自学习策略后,怠速转速稳定且一致性较好,转速波动小于±15 r/min,满足工业化生产目标控制要求。

In order to reduce the idle speed fluctuation during the cold start and warm-up phase of the vehicle,a self-learning control strategy for fuel injection based on the speed fluctuation is designed.Compared with the traditional proportional integral differential(PID)control,the fuel injection self-learning strategy increases the fuel injection adjustment based on the speed fluctuation,monitors the speed fluctuation pattern and modifies the fuel injection pulse width.A real vehicle test is carried out to study the consistency of idle speed stability at the same environmental boundary,and the speed fluctuation as well as the probability distribution of speed fluctuation before and after the implementation of the fuel injection self-learning strategy are compared and analyzed.The results show that the idle speed consistency is poor without the fuel injection self-learning strategy,the idle speed control cannot converge,and the speed fluctuation is greater than ±50 r/min.When the fuel injection self-learning strategy is implemented,the idle speed is stable and consistent,and the speed fluctuation is less than±15 r/min,meeting the control requirements of industrial production objectives.