Fuzzy PID Model -Based Study on Idle Control of Gas Engine

Abstract

Nowadays, natural gas conforms to the conditions of environmental protection and renewable energy, which plays a significant role in the future development of mankind. It has made some progress in applying natural gas to the automotive industry. As we all know that the source power of automobile comes from engine, therefore, based on the study on the control algorithm of gas engine, this paper aims to provide theoretical basis for further application of gas en- gine. This paper analyzed PID control algorithm, fuzzy control algorithm and fuzzy PID control algorithm, designed cor- responding controllers based on the algorithm principles, applied these three algorithms to the idle control process of the automobile gas engine. This paper concluded that the fuzzy PID control algorithm is of higher superiority through con- trastive analysis on the control effects of theses three algorithm in the process of cooling high idle start, switching high idle to low idle and switching low idle to high idle. Natural gas engine came into being in 1872, Italian used natural gas as the automobile fuel in early 1930s, gas vehicle technology developed rapidly in 1970s, and gas-fueled vehi- cles skyrocketed after 1990s. Nowadays, the bi-fuel single- point injection system and mono-fuel closed-loop multi- point sequential fuel injection system came into being in succession, and the closed-loop multi-point sequential fuel injection system is the mainstream and direction of the elec- tronic control technology of gas engine in the modern times. The exploration and application of the automatic control algorithm of the gas engine is the major studying content for relative scholars. Under this background, this paper analyzed the PID control, fuzzy control and fuzzy PID control algo- rithms (1-4), and targeted to explore the application result of these three algorithms in the controlling process of the idling system. Numerous researchers had made contribution to the study of gas engine control, and it is these researchers' efforts that promoted the development of automatic control and the in- tellectualization process of gas engine. Among which: Wu Jianping (2010) studied the air-fuel ratio control strategy for gas engine in different operation conditions, and designed a kind of fuzzy PID dynamic switching control algorithm and simulated this algorithm in Simulink, and the result showed that this algorithm is of better real-time performance, stability and robustness (5). Zhiming, et al. (2011) trans- formed the diesel engine of a certain model to make it appli- cable to gas generator set, to demarcate lean-burn and 1500RPM addition & subtraction load, and demarcate the spark advance angle on electronic control system under the