Rhythmic pattern recognition technologies of an acoustic wave have been attempted to control electronic gadgets like earphones, displays, mobile devices, etc. But, in the aspect of realization, previous methods for classifying and recognizing the rhythmic patterns are not easy to maintain a program structure due to complex comparative grammars and equations. It could be more difficult to implement those methods on a micro-controller of low clock speed and small memory size. In this paper, a novel rhythmic pattern recognition technology is proposed to solve these problems with a new polynomial equation. The proposed method can instantly classify diverse rhythm patterns and be immediately implemented even in various rhythm numbers and intervals. The effectiveness of the proposed algorithm is shown in a real headlamp system.