Fractional fourier transform and its application to engine knock detection

The fractional Fourier transform (FRFT) is a generalization of the well-known Fourier transform. The FRFT depends on an order parameter a and can be interpreted as an a-th power of the ordinary Fourier transform operator. This tool has found widespread applications in areas such as optics, wave propagation analysis, signal and image processing, solving of differential equations, mechanical vibrations analysis, quantum mechanics. The paper focuses on the use of FRFT in an automotive application to estimation of the knock intensity in a spark ignition engine. The obtained results demonstrate that the proposed method provides high accuracy with low computational complexity.