Phase-based time domain averaging (PTDA) for fault detection of a gearbox in an industrial robot using vibration signals

•We propose a new phase-based time domain averaging (PTDA) method.•A systematic approach is proposed to detect fault of a gearbox in an industrial robot.•The proposed method is demonstrated by the experimental data from a six-degree-of-freedom (6-DOF) industrial robot test-bed.•The proposed method shows better performance compared to the previous method.