Dsp based processing of vibration signals of varying frequency

This paper presents the first step of the development of a PC-based system for the determination of synchronous frequency, amplitude and phase of moderate to rapidly varying frequency vibrations. The system uses a PC-DSP configuration for which a synchronous filtering algorithm was programmed. Time domain zero crossing algorithms were used as a preparatory stage for the computation of the vibration parameters even in the case of rapidly varying frequency vibrations. The effectiveness of the system was evaluated using experimental rotors. The system promises to be a simple and economic tool for modal analysis and rotor balancing.