【摘要】 汽油机爆震边缘检测是汽油机点火闭环控制的前提,也是爆震检测的难点。提出了一种利用分形几何检测汽油机爆震边缘的方法。研究表明,分形维数在爆震边缘附近变化明显,可以作为爆震强度指标判别爆震边缘。利用分形维数不仅能够自缸压信号中有效检测出爆震边缘,而且能够自振动信号中有效检测出爆震边缘。由于分形维数本身可以作为爆震强度指标,因此分形维数兼具爆震检测和爆震强度判别两种功能。更多还原

【Abstract】 Knock threshold detection is the key of closed loop control of ignition in gasoline engine,and it is also the difficult point in knock measurement.In this paper,a fractal based knock threshold detection meth-od is presented.lt shows that the value of fractal dimension gives large change at knock threshold and can be used to evaluate the knock intensity.Fractal dimension not onlg can be used to detect the knock threshold from the cylinder pressure signal,but also can be used to detect the knock threshold from the engine surface vibration signal.Since fractal dimension itself can reflect the knock intensity,thus it has the functions of knock detection and knock intensity evaluation。更多还原