Abstract: Aiming at the problems of order tracking method, such as extra installation of speed measuring devices, low precision of speed acquisition compute methods, and weak antinoise ability, a new order tracking gearbox fault diagnosis method based on Chirplet path pursuit in instantaneous frequency estimation is proposed. Taking the advantage of the said estimation which is suitable to decompose nonstationary signals with frequency variation curve, the method takes speed signal by estimating the gearbox’s meshing frequency component. With the speed signal, it carries out even-angle resampling on even interval sampling signals, transfer non-stationary signals to angular domain stationary signals, and acquire the order spectrum of vibration signals, so as to judge the fault of gearbox. Simulation and application examples prove that the method is of high precision and antinoise ability, which, based on its own features, can adaptively choose base function, and accurately estimate the speed, whose combination with order tracking method can be effectively used in gearbox fault diagnosis.

Key words: Chirplet path pursuit, Fault diagnosis, Order tracking method, Signal processing