DESIGN OF ELECTRONIC CONTROL GOVERNOR FOR A SINGLE CYLINDER GASOLINE ENGINE BASED ON AN INTELLIGENT SENSING ALGORITHM

ABSTRACT At present, most large machinery and vehicle engines are electronically controlled but their electronic control systems are too expensive to be popularised and applied in small gasoline engines with relatively low prices. Therefore, small gasoline engines still use mechanical speed regulators. Mechanical speed regulators not only have the defects of inertia lag, friction resistance, inherent speed regulation and the like, but also have the disadvantage that dynamic performance and steady performance cannot be combined, which is not suitable for the increasingly improved speed regulation performance of gasoline engines. This paper describes the design of an electronically controlled intelligent governor for small gasoline engines. Starting from a low cost, it adopts the idea of “replacing part of the hardware with an intelligent sensing algorithm” and proposes an intelligent sensing algorithm scheme. It combines the “coarse tuning” of MAP and the “fine tuning” of adaptive expert PID. The system is proved experimentally and it not only overcomes the inherent defects of a mechanical governor and realises programmable speed regulation, but it also obtains good dynamic and steady performance, improves the power output of the engine, relieves the trouble of engine travelling and improves the freedom of carburetor matching.摘要 当前，绝大多数大型工程机械与车用发动机均已采用电控技术，但其电控系统成本过高，难以在价位相对低廉的小型汽油机中推广应用。因此，小型汽油机目前仍普遍采用机械调速器。机械调速器不仅存在惯性滞后、摩擦阻力、固有调速特性等缺陷，还无法兼顾动态性能与稳态性能，难以适配汽油机日益提升的调速性能要求。本文阐述了一款面向小型汽油机的电控智能调速器（electronically controlled intelligent governor）的设计方案：该方案以低成本为设计出发点，采用“以智能感知算法替代部分硬件”的设计理念，并提出了智能感知算法方案，结合了MAP的粗调与自适应专家PID的精调功能。经实验验证，该系统不仅克服了机械调速器的固有缺陷，实现了可编程调速，还获得了优异的动态与稳态性能，提升了发动机的功率输出，缓解了发动机游车的故障，同时提升了化油器匹配的自由度。