Study on the effect of fuzzy PID air-fuel ratio closed loop control of a natural gas engine

摘要

The air-fuel ratio (AFR) control becomes an important research direction in gas engine. This article conducts air-fuel ratio (AFR) closed loop control research in a CNG engine. The injection pulse width of gas is controlled by a controller, oxygen sensor signal as a feedback signal. In order to make the engine can achieve the anticipated air-fuel ratio under different conditions; we adopt fuzzy self-tuning PID control strategy based on feed forward control. We transformed a 2135G diesel engine into the single fuel gas engine. Experimental investigation on the effect of air-fuel ratio closed loop control. Experimental results shows that, fuzzy self-tuning PID control strategy can control CNG engine air-fuel ratio working in the good condition.