多点电喷气体发动机空燃比闭环控制系统设计

Air Fuel Ratio Closed-loop Control System of Multi-point Gas Injection Engine

摘要:

空燃比控制是发动机性能实现中最重要的控制之一。基于玉柴某大型六缸单点气体发动机改多点电喷的基础上进行研究,在开放式ECU基础上针对燃气发动机瞬态变化过程中的反馈时间延迟,构建了一种基于前馈PID算法的空燃比闭环控制策略,用来预判和补偿空燃比超调和反馈时间延迟；解决了发动机瞬变工况下空气与燃气的精确匹配问题。通过对台架模型和发动机试验的数据分析,结果表明基于前馈PID控制算法的空燃比闭环控制策略能够进一步提高燃气发动机的排放效率和动力性。

Abstract:

Air-fuel-ratio control is one of the most important part to achieve engine performance. This electronic control system is based on a large six-cylinder gas engine of YuChai. Based on open ECU, it propose a kind of forward PID algorithm for the feedback time delay about transient change process in air-fuel-ratio closed-loop control system of Gas engine. This PID control algorithm is applied to estimate the overstrike of AFR and compensate the feedback time delay,which solved the exactly match problem of air and gas in the transient condition. The data analysis of simulation and the results of engine test shown that the AFR closed-loop control system based on forward PID algorithm can be used to improve the discharge efficiency and the power performance of gas engine.