공회전 안정성 향상을 위한 실린더별 점화시기와 공연비 제어에 관한 연구

Abstract

This study aims at the enhancement of idle stability through individual cylinder ignition timing and A/F ratio control, In four cylinder engines, angular velocity for a cycle shows four max. and min. points because of four expansions and compressions. And the difference between max. and min. angular velocity is proportional to the power of each cylinder, Ignition timing is a very important factor in engine power and at idle, A/F ratio difference among cylinders are relatively larger. As the power differences among cylinders are reduced. The cycle variation of engine speed can be also reduced and then the stability is much better. Therefore, individual ignition timing and A/F ratio control are carried out respectively to improve the idle stability. The STD, the difference between max. and min. of angular velocity, and PSD though FFT were investigated to represent the idle stability objectively. In these points, the experimental results showed that both individual cylinder controls can enhance idle stability.