US 12,411,482 B2
Signal processing method, signal processing device, and monitoring system
Kenta Sato, Shiojiri (JP)
Assigned to SEIKO EPSON CORPORATION, (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Aug. 19, 2022, as Appl. No. 17/891,446.
Claims priority of application No. 2021-134719 (JP), filed on Aug. 20, 2021.
Prior Publication US 2023/0055678 A1, Feb. 23, 2023
Int. Cl. G05B 23/00 (2006.01); H04B 17/26 (2015.01); H04B 17/309 (2015.01)
CPC G05B 23/00 (2013.01) [G05B 2219/37434 (2013.01); G05B 2223/02 (2018.08); G05B 2223/04 (2018.08); G05B 2223/06 (2018.08); H04B 17/26 (2015.01); H04B 17/309 (2015.01)] 10 Claims
OG exemplary drawing
 
1. A signal processing method for causing a processor to execute a process, the signal processing method comprising:
a sensor placement step of mounting a first sensor and a second sensor on an object including a motor, the first sensor and the second sensor being configured to detect a first acceleration of a first axis and a second acceleration of a second axis generated by a vibration of the object, respectively; and
executing on the processor the steps of:
a measurement data acquisition step of acquiring first measurement data based on a signal output from the first sensor and second measurement data based on a signal output from the second sensor;
a Lissajous figure generation step of generating a Lissajous figure based on the first measurement data and the second measurement data;
a polar coordinate transformation step of transforming coordinates of each point in the Lissajous figure into polar coordinates and generating time series data of a first angle which is an angle formed between the first axis and a straight line, the straight line being obtained by projecting a straight line passing through an origin and each point in the Lissajous figure onto a plane including the first axis and the second axis;
a first angle maximum peak intensity calculation step of executing frequency analysis on the time series data of the first angle and calculating a first maximum peak intensity which is a maximum peak intensity in a first frequency spectrum obtained by the frequency analysis; and
a state determination step of determining whether the object is operating abnormally by comparing the first maximum peak intensity with a first threshold value.