State monitoring method, state monitoring device, and program for mechanical device

A state monitoring device for a mechanical device that performs a rotation operation, the state monitoring device comprising:

• an acquisition unit configured to acquire rotational speed data and vibration data during the rotation operation of the mechanical device;
• a conversion unit configured to convert the vibration data from a time domain to an angle domain using the rotational speed data and the vibration data acquired by the acquisition unit;
• a reconversion unit configured to reconvert the vibration data converted by the conversion unit into a time domain based on a predetermined reference speed;
• and
• a diagnosis unit configured to diagnose a state of the mechanical device using the vibration data converted by the reconversion unit, wherein
• when the rotational speed data includes a section in which a rotational speed is zero or substantially equal to zero, the conversion unit corrects the rotational speed data such that the rotational speed fluctuates in the section, and then converts the vibration data into an angle domain.

A program that causes a computer to execute:

• an acquisition step of acquiring rotational speed data and vibration data during a rotation operation of a mechanical device;
• a conversion step of converting the vibration data from a time domain to an angle domain using the rotational speed data and the vibration data acquired in the acquisition step;
• a reconversion step of reconverting the vibration data converted in the conversion step into a time domain based on a predetermined reference speed;
• and
• a diagnosis step of diagnosing a state of the mechanical device using the vibration data converted in the reconversion step, wherein
• in the conversion step, when the rotational speed data includes a section in which a rotational speed is zero or substantially equal to zero, the rotational speed data is corrected such that the rotational speed fluctuates in the section, and then the vibration data is converted into an angle domain.